Have you considered teaching? I've been substitute teaching since I graduated two years ago, and I'm about to get my certification to become a real teacher. If you mainly work at high schools it will be just like skating after school back then. I have plenty of planning periods through out the day to accomplish work so I am usually pretty free after getting off. I know several teachers who skate most days out of the week. Also the health insurance is usually pretty good in most school systems.
Only partially true. Plenty of planning periods throughout the day? Where the fuck do you work? I literally have to treat my day like I have no planning periods, because despite having one, more than half of my days I have to do what is called "period subbing" to make up for missing teachers and a shortage of subs. Along with that, even if I don't have to period sub, the amount of work I have to do means that I take home and work on a bunch of things every single day.
Summers are fucking sick though, aside from the fact that none of the rest of your adult skate friends will be off.
The issue with getting older is "how important is skateboarding to you?" If its important, schedule it in, make time for it.
Another thing is not to be dependent on friends to go skating. Obviously skating with friends is great, but a lot of times during the week, due to time constraints, I'll just go straight to a spot or skate park just to get some time in before the sun goes down.
Also, don't drink much. So many of my friends have completely fallen off due to their excessive drinking. Not only do hangovers and time spent at bars cut into your skate time, but as you get older, hangovers get worse, and skating with one gets harder.
A bonus nobody is telling you about is the adult sleep schedule. When you are up 5 days a week before 7 am and don't need that teenage amount of sleep, you can wake up saturday morning at 8 am feeling rested. This makes the skateable (aka sunny) part of the day longer, giving you more time to skate and get anything else done.
One other huge thing: skate when you are tired from work if you aren't doing manual labor. When my brain is fried from work, one of the most refreshing things for me is to get myself on the board just pushing. Just getting out in the sun, doing something physical, distracting myself from the stress of life and getting into a different mental place is so fucking therapeutic and leaves me feeling energized and more able to get through the work week. So make sure you find that time, because believe it or not, it will benefit your career life too.