I smoked weed moderately to heavily as a teenager and lightly to moderately through most of my adult life and kind of just got tired of it like you.
I've always been able to achieve pretty much anything I set my mind to but looking back on my life, I think the weed use made me achieve less than I normally would've by this age and it definitely made me apathetic in a lot of areas which caused me to make some very wrong decisions in regards to certain opportunities that I squandered. (It also makes me write run-on sentences. :o)
It's that old 20/20 hindsight kicking in now that I'm in my 40's and won't have some of those opportunities back.
The best antidote to excessive self destructive pot use, which causes the caution, and the moderation, is a burning ambition to achieve one's goals, that one has set for oneself, in which one's ego heavily invested, and which becomes a rather hard wiring and almost consuming matter of self respect. I wish I could put it better, but that is my experience. But man oh man what it fun, in certain contexts. It was grand!
Back in the 80's there was a superb anti-drug commercial.
A young man 20ish is smoking grass with his friend watching TV in his room. They see an anti-grass commercial.
"I'm tired of all this stuff about how marijuana messes you up. We've been smoking it for 10 years. I never got into other drugs. I didn't go out robbing people. It didn't make me do anything different. Nothing happenned. In fact, I'd say I'm the same as when I smoked my first joint."
Then we hear his mothers furious voice from downstairs.
"DID YOU EVEN LOOK FOR A JOB TODAY !!! ?"
"Uh, no, Ma"
Voiceover.... Marijuana can make nothing happen to you, too.