there is a fine line between voicing and coming over as i know best, you can give your opinion and not loose your temper, i never shout or loose my temper in the usual way, i just get very clipped, i won't say something if i know it is going to upset someone or cause hurt, if i really need to voice my opinion i just say that is what i think and leave it at that. i have noticed in the last 10 years i am much calmer and less things bother me than they did when i was younger, i am 62 and my thought process is more of a whatever attitude. try not to cause problems with the people around you as these things can fester and people will not what to spend time with you, and that is not worth it, bite your lip and walk away.