My two younger brothers are still kinda young, 17 and 15, so I don't really want to make them feel pressured or anything.

I started when I was 15, right before high school, when a good friend of mine and his sister were smoking a joint and passed it to me. I had turned weed down before, but I tried it then because it was a comfortable setting, and I've been a (mostly) nighttime toker ever since.

I don't regret starting to smoke, but I regret starting as early as I did. Instead of pursuing extracurricular activities after school, I got stoned with my close circle of friends and played video games or other fun activities, but I didn't realize at the time that every day I did that, I was giving up doing something new, or learning a skill, or literally anything else I could have done as a youth in suburban America.

Granted, I played WoW in Jr. High, and with my comfortable circle of friends whom I still talk to today, I was never very outgoing. However during high school and in the beginning years of college I picked up both the guitar and weightlifting, both of which I enjoy very much and do as often as I can. I had alot of fun smoking as a teenager, but I can't help but think how good I could have gotten at guitar, or how much more impressive my physique could be now.

As an adult, smoking after work, or after working out is a great feeling, because I've learned to use it to reward myself for a good day, instead of smoking as a supplement to doing something productive or engaging. But again, I had to learn how to do that, and how to involve it in my life without letting other aspects of my life suffer.

Sorry for the rant, hopefully you can incorporate this line of thinking into your approach with your siblings.