Well I am 43 and I have been smoking since I was 17.(no ill effects)
Always in moderation since I am pretty healthy I just limit my use on the weekends.
I love it and the older I get I think the better is for me, one thing it does It makes me sleep much deeper, which lately I am having problems with.
For the last few years I been getting organic stuff and really makes a difference, I never have any drowsiness the next day.
In fact makes me more active and energetic.
My favorite thing to do stoned is to walk in the woods with my dog.
I allways dicover somthing new and amaizing, especialy about my self, also like some other posters said I have become very body aware, because of pot I have learn taichi and shiatsu.
Cannabis has been a greate teacher for me and so many aspects.
I tend to like sativas, my only advice is to treat it with respect and unless you suffer some illnes also in moderation, because even good things if done to much turn bad.