I think you just did. I believe in the "addictive" personality. And in a lot of cases, drugs or alcohol are used to "cope" with life. Someone doing pot, in my mind, is no different than a drunk or an addict. And if you want more out of life & he doesn't, then it won't work. If your gut told you something was wrong...go with it. Read up on addiction. My ex started years ago on pot. And it lead to crack. He started out functioning. He had everything he wanted. He was on top of the world. Then the drugs slowly but surely brought him to the gutter. He threw away his potential. He threw away his future. He threw away a woman he'd waited 16 years to have in his life. All because drugs & booze were the most important thing in his life. It took him about 18 years to end up in prison & lose it all to drugs. He came out. Started a new life. Ended up right back where he started & at 43 he has nothing of his own. Just a few clothes. For everything else he has to rely on someone else.
Is that what you want your life to be?
Lynne