I am the first line tech support for my office. Here is how my support calls usually go, when a user calls me with a computer problem:

1) 33% are solved by the usual means:

User: "I have this problem..."
Me, cutting user off in mid-sentence: "Did you try rebooting?"
User: "Um, no."
Me: "Try it!"
Later user calls back: "Thanks, that worked!"

2) If I pay a personal site visit to observe the problem, another 33% can't be reproduced, so that gets me some exercise and solves another 1/3 of the problems. User complains about it: "But it kept doing it before you were here!" Well, I must have magic powers or something, I guess...

The remaining support calls require work, and it only takes one nasty problem to screw up your day, but that's still a lot of easy fixes.