Weed is similar to pills, if you are in a good mood when you take one, your good mood will be intensified, while if you are depressed/bad mood, your depression will be intensified. I know from personal experience.
I don't smoke cigarettes, but don't mind the smoke of weed, cause the smoke is scented, plus you'll be relaxed so you don't really give a shit. At least thats how it is in Malta