Personal anecdotal experience.

Smoke for the first time at 31.

Been nearly a decade since then.

I intentionally keep my tolerance low, and only smoke when I'm writing (I often write for several hours at a time). I have found it to be a very useful tool for creative thought, it's like a mental lubricant for me. I am just a creative without it, but ideas flow more readily when I've had a little puff.

Not everybody is cut out to be a shaman like me. Don't smoke while you're brain is still developing, keep your tolerance low, and smoke only with a specific intention in mind, and it's possible to gain real benefits from weed. But for 99% of people, it's probably not good for them.

There was a brief period when I first started smoking where I was smoking too much, but I recognized the slippery slope and then created a living situation which removed the constant temptation from my home environment. I now have a place I go to for writing and smoking, but not everyone has this luxury.

Good luck.