I became a regular smoker at the late age of 40, after getting my med card.
Aside from the medical benefits for which I got the card, weed has:
Helped me overcome my math anxiety and improved my ability to learn by about 400%. I actually understand math better since starting the weed. Also, I have severe ADHD and can only learn stuff if it's something I'm super interested in. But when I've had a little weed, I'm interested enough to learn my school topics (I went back to school a few years ago).
Helped me have spiritual insights. Got me to have a deep interest in science, philosophy, religion, mysticism, mathematics, and other really abstract topics to a level that I never had before.
Helped me to understand and appreciate music so much.
Helped me have life-changing insights about people and social life. It improved my social skills a million times over. There are little social niceties I never got before I started smoking. But on weed, I started to actually enjoy small talk. I've been able to carry this over to real life.
Improved my relationship with my mom 100% (my mom got her own card, and we smoke together once or twice a week). We fired our family counselor after starting our sessions with "Counselor Herbie".
All of these benefits carry over to my non-stoned life - i.e., if I mastered something while stoned, I don't need to be stoned to do it again. If I do it too much, too often, after a while, it's diminishing returns.
I was on Paxil for anxiety but it didn't benefit me the way weed has. I've actually been able to ponder the sources of my anxiety on weed and *get over it* whereas Paxil just... medicated it.