I'm not sure about this(I'm 30 btw), when I was playing the NES games back in the days(also this applies to PS1 games), I had to learn everything on my own, I've finished a lot of the games too, today, people have easy access to guides/walkthroughs through the internet which I didn't have at all(internet/game guides). Heck Ninja Gaiden alone took almost 2yrs just to finish, just because I stop games when it's really getting hard for me, then I play other games then go back to the games that was really hard for me to finish.
Edit: Skills / reaction time wise, I've gotten really better, heck the souls games/bloodborne really isn't a challenge for me anymore after a couple of hours of playing(2hrs max), yet I gotta admit, I have to search for guides just for the secrets( I just don't like missing out on secrets :D).