Every generation comes up with its own ways of making life easier (or simply "hacking" the system)! However, as technology evolves, this once-common knowledge often becomes obsolete...

That's why when Redditor u/MittlerPfalz asked, "What was a cool 'life pro tip' or 'life hack' that you used back in the day that is no longer relevant or possible?" hundreds of people over 50 shared "hacks" from their younger years that are irrelevant now. Without further ado, here are 19 of their most surprising responses:
If you know of any once-common knowledge that is unusable in today's world, feel free to tell us about it using this anonymous form!
1. "Hacking pay phones: To understand this hack, you need to remember analog pay phones, where you would dial the number and then an operator would come on and say something like, 'Please deposit $2.25 for three minutes.'"

2. "When shopping, we never picked the item in front but rather reached for the one in back to get a lower price."
"Oftentimes, the clerk restocking would be lazy and not re-price the ones already on the shelf. Of course, this was back when price stickers had to be manually put on each item."
3. "When I was transferring from a local community college to a large university, my grades were less than stellar. At that time, college transcripts were written in ink on a paper form that you took with you when you registered."
"I discovered I could erase just enough of the ink marks to change a couple of 'Ds' to 'Bs.' It worked like a charm!"
4. "Roughly 1980: Maryland and Virginia didn't share driver's license information, so I had one for each state. My auto insurance was tied to one driver's license, and whenever I got pulled over for anything, the points went against the other license."

5. "As a broke college student, I couldn't get a credit card, and I got a monthly check, so things got tight during the month (this was in the early '70s before debit cards)..."
"To help me out, my older brother taught me this: Sears would issue a store credit card to college students. I used it to purchase a gift certificate for, say, $40. I would then use the gift certificate to buy a couple of pairs of socks, and then they gave me the rest in change. $30-35 went a long way back then. At the end of the month, I would pay the bill, then rinse and repeat.
I kept (and used) my Sears card for many, many years."
6. "I used to place a baby monitor transmitter near the TV and carry the receiver around with me while doing chores and yard work. It was my pre-Bluetooth. I had several of the Fisher Price models, which were purchased frugally at yard sales."
"It was good for listening to breaking news, QVC, or shows where I didn’t really need the video to follow along and keep my mind occupied during menial tasks.
Now I play Sirius or Audible from my phone."
7. "When I was a kid, I was watching a guy service a vending machine and asked if I could have a free candy bar. He said I couldn't, but that I could have the 'slugs,' which were fake quarters in the coin compartment. As soon as he left, I tried the slugs and sure enough, they worked like quarters and I was able to buy a few bars."

8. "It used to be recommended that folks carry a small disposable camera in the glove compartment of the car to take photos in case of an accident."
"Nowadays, just about everyone has a camera-equipped phone, so this isn’t necessary anymore."
9. "If you went to a government office to apply for something and they handed you a stack of forms to fill out, you could just stand there and tell them you couldn't read or write, then they had to read you the questions and write down your answers. It was way easier than doing it yourself.'
10. "I read Steal This Book, and it said if you just looked like you belonged somewhere, people wouldn't question you, and pre 9/11, this was always true."

11. "My family kept a large glass water bottle. Every day, my Dad would empty his pockets of loose change and encourage me to toss coins in, too. I was a kid, so I don't remember how long it took to fill up, but one day, he laid an old sheet on the ground and emptied it. We spent the weekend rolling coins."
"Fast forward to now, and I can't remember the last time I had change in my pocket."
12. "Unplugging the house phone extension, taking the receiver off the cradle, and then plugging the phone back in was my favorite hack."
"The people talking to each other on the phone (like my sister and her boyfriend) didn’t hear someone pick up the extension to listen to their phone calls."
13. "Where I grew up, there was a local phone number you could call to get the correct time. Not a whole lot of people knew what it was, though, so if I were at a club and someone was obnoxiously pestering me for my phone number, I would give them the 'time number.'"

14. "In an old car with a carburetor, it was possible to 'flood' the engine while trying to start it when cold, and it was difficult to get it started after that..."
"The 'hack' was to very slowly push the gas pedal all the way down (this was so the accelerator pump in the carburetor would not squirt a shot of raw gas into the engine, making the problem worse) and then count to 10, which allowed the gas in the the manifold to evaporate, then let the gas pedal up maybe half way, then turn the key and try again.
It sometimes worked."
15. "When creating masters for the mimeograph machine, errors could (mostly) be corrected by carefully using a razor blade to scrape off the ink image on the stencil. The tricky part was trying to get the stencil back in your typewriter and return to that spot with the typewriter properly aligned."
"Releasing the roller so it was free and carefully, very carefully positioning the master back to where you cleaned off the mistake before locking the roller in place again completed the 'erasing' of the mistake. It was difficult, but still much better than starting over with a new master. Inexpensive copy machines made them all obsolete."
16. "I used a Rolodex in my job to make notes about clients so that when they called, I could quickly flip to their card and make a small personal comment like 'How was that trip to Italy?' or 'How is your new puppy working out?'"

17. "Beginners tip: We had to get to the bank early Friday to cash our paychecks and avoid the rush — no ATMs, no Saturday banking, no debit cards."
"Payday was every Friday, and we needed to get that money in the bank so we could write a check at the grocery store. Bankers' hours were a real thing; they opened late and closed early.
Now for the pro tip: Some grocery stores would cash your paycheck."
18. "I would write the combo to a lock on the back with a secret code written on masking tape. If I forget, I checked the back of the lock: I used the word 'QUICKTRADE.'"
"Q=1, U=2, I=3, etc.
But now it's just as easy to save your combos on your phone or other digital places
It still can be useful if you're gonna throw a random lock in a shed, basement, or some other place where it might sit for years, but it's just not as useful as it once was."
19. "Columbia House Record Club: You joined and got 10 or 12 albums for free, then had to buy six to ten in the next few years. In the 1970s, they sent you a card each month. If you didn't return the card, you got the featured album in the mail. If you sent the album back, it counted as if you bought it, lowering the number you had to buy."

Did any of these "hacks" surprise you? People over 45, what are some other things that used to be considered common knowledge that are now obsolete? Tell us about it in the comments or answer anonymously using the form below!
Note: Some responses have been edited for length and/or clarity.