I'm 44, too sedentary, out-of-shape, and wasting time on video games lately. I'm ADHD-PI with timeblindness, tangents, procrast, and overfocus. I have monofixation syndrome (MFS) that I never knew I had until my new old-timer opth found incidentally.

Stress maybe? How's your Maslow's sleep, diet, exercise, and mood?

Also, consider that age comparing now with peak performance of say 15-20's is unfair. Give yourself a break.

Maybe a sabbatical is in order.