[fatalerrorx3]

I'd say the best thing to master is solving problems.

In the case of developers it may mean that you never become a master at programming, but what's more important: solving a problem or having elegant, well documented non-solutions?

Hackers make things work, and I think that's more important than being a "master" - I don't even like the word master, it almost feels egotistical.

[milfot]

Hackers (by my own definition) make this thing here work now.

A master of his art has the time to design not just his solution, but the task itself, and the experience to understand all the implications of a given solution.