Hahahahaha... 15 years ago you did this shit 12 hours a day... do that course a few times and you'll be right as rain, kids.
I started forcing myself to up my DPI as I had become lazier and lazier over the years... I rock that shit at 5500 DPI again. Several other exercises to force the brain to do shit that maybe isn't as comfortable as it was to do back then. Use it or lose it, right?
I think 90% of why gamers that are aging suck is because they just chalk it up to age and move on. Not to mention the proliferation of hacktards these days.
Countless people (myself included) get discouraged too quickly because they aren't immediately leading the board in any given game. GTA V I got shrekked at first... gave it a couple dozen hours and focused on what I was doing more (which is tough since it's a really fun game to get hammered whilst playing) and Truck and I were dominating fuckers out on the pubs... Mackmeel joined us and a couple others and we'd clear whatever area of the city we were in at the time.
Same with Chivalry... I fucking ragequit that game a dozen times... played it a few times sober, watched a few tutorial vids... and top of the boards, even on servers with level 40-60 people on there.... peeps just need to take their lickin a few times and keep trying... pansies.