It takes more time effort to learn new stuff.
It became very easy to get injuries doing sport or even just working out.
I don't get hard as fast, no longer risk to cum on my face when jacking off, and need a lot more time to make repeat.
I know a lot more on vastly larger number of subject. Underclocked CPU but huge hard drive.
I have so much knowledge on my body I can find creative ways to navigate between my limitations, and take more pride in my success.
I'm no longer slave to my hormons, and improve day after day my sexual skills, like everithing that happen before you finally ejaculate ;-)
20 was hawsome yet difficult. 30 too. 40 too. Making plans for 50.