I grew up with an Atari 2600 that was connected to a small color TV. Eventually, that same TV was used with the NES, but it wasn't until the NES that I learned that TV had a serious flaw. The bezel on the TV actually covered up part of the image so that I was unable to see the edges of some games. I learned this playing Metal Gear and was just utterly stuck. I wound up buying a magazine with hints for the game, and started comparing the screen grabs in the 'zine to what I could see. It wasn't until quite some time later that I asked someone and they told me about overscan/underscan. I took the TV to some repair place, and they opened it up and adjusted it (there was no switch to enable underscan).
The things kids today will never have to endure /s
Ha, I too had the pleasure of playing Metal Gear on an old CRT that had a similar bezel that covered the sides of the screen. I too had the pleasure of going crazy trying to figure out what to do. Good times.