Weed makes consumption more enjoyable, therefore you consume more than you'd consume without weed, at the opportunity cost of doing other things. Which in general makes you more boring.

I've been around stoner friends a lot (for most of them it was a phase in life which they got out of before ~30) - no matter how boring / interesting they were before / after weed, during their weed days they were more boring than during their non-weed years. Weed makes you content just sitting at home while otherwise you'd rather seek some excitement outside.