The problem with that is you usually don't see the results of your work. Let's say you work for Mozilla on Firefox - even though you only make trivial contribut

The problem with that is you usually don't see the results of your work. Let's say you work for Mozilla on Firefox - even though you only make trivial contributions (because a single person cannot do much), those contributions multiplied by millions of users can be significant. The problem is that you have no way of experiencing it - you can only imagine it/think about it. In a similar story, I've heard about environmental lawyer who was doing a ton of good for the environment but personally felt crappy, because he was just spending 10+ hours a day shuffling paperwork or in front of a computer.