@djsumdog @xianc78 @dubh It's relatively safe for most people if you don't start too young and don't overdo it, I'd say.
For lungs, just vape flowers well flushed from nutrients..
The most important thing is to have time to recover between sessions (at least couple of days, but weeks is better) so that your brain won't forget how to function normally without it. Otherwise it will fuck up your life. Though, the damage is still less severe than with alcohol, benzos or coke that are comparable.
@djsumdog @xianc78 @dubh It's like a heavy backpack. If you have it on your back from time to time, it's fine. If you have it on your back too often, your back will start to compensate and get deformed.
Taking care of having a healthy and strong enough back for the backpack (or head for cannabis) is also important.
Btw, you might be on edge because you're overworked if you're doing more than you are used to. Could not be cannabis related at all in that sense.
It does make it more difficult to code, write and focus .. although it can be better for things like working on music.
I've smoked it off an on throughout my life. I think it should be legal, I'm not so sure it's entirely benign as many, myself included, have said for years. I want to get around to reading Alex Berenson's book about it; just to get the other perspective.