Confused....

Should I? Or should I not? People have told me to weigh the pros and cons, to do a cost-benefit analysis, but is it as simple as putting all the good on one plate and the bad on the other? This isn't arithmetic... I can't bloody put things in a black and white scale, and do simple addition. Every action has a reaction. Every thing that happens is an effect of an earlier action, and is a cause for a later action. Damn...why must things in the world be so intrinsically interwined? If saying so, won't that make everything and everyone be unprofessional? What is professionalism? Is it being able to block everything else that has no direct impact on the situation out of the equation? One has to keep all other thoughts and distractions out of one's mind, in order to be completely focused on the job at hand. But if every action has a reaction, which becomes the cause of a later effect, then how can one be completely insulated from the world around? If so, can anyone really be professional?