Not really fun, and if he's ignoring you, just threaten to beat him if he doesn't pay attention to you. Or take him away from the computer, he'll appreciate it.
It can be interesting and boring, tedious and fun, stressful and relaxing. It all depends on what is going on. Some times its relaxing cause the code doesn't require much thought, being thought out before hand. Other times it can be tedious (debugging) and annoying.
As far as teaching a computer how to do trig homework. It wasn't that hard, just took some time. The hardest part is the fact that computers are really stupid, and do exactly what they are told to do, with out thinking about it. (Which is probably why they haven't replaced humans everywhere either)