Spending 2 years in hell doing phone tech support for an ISP after high school was probably the most valuable career experience I've ever had bar none.
Nothing has prepared me for making and selling software to regular people better than this experience. Entire assumptions about how users interact with computers, ones based on my own experience, were rendered useless.
The ways regular people think about technology is endlessly fascinating because it very rarely has anything to do with how I think about technology.
At my day job, we eventually decided to put our development lead as tier-2 tech support because we couldn't get this across. He receives every single piece of support mail we get and is asked to respond to a pretty good percentage of them.
It's been a 2 year, very difficult, education for him.