[MrHobbes]

"Maybe it has to do with the problem domain, but I have a hard time accepting that."

Your profile says that you are a web application hacker. I think that explains why you may not feel that data structures or algorithms are important. I was the same way myself (started my programming life by building Perl cgi scripts, made a nice little cms, definitely didn't use any fancy stuff to do that).

You should take it from me though. You will suddenly develop a deep and profound appreciation for understanding algorithms when you have a problem that requires having to comb through over a hundred thousand records, perform some type of operation on them, and sort by the results of that operation - all within a fairly narrow time period.

I think that it actually is a question of problem domains. If you never encounter this type of problem, then not knowing about things like big o notation and the various sorting algorithms will never impact you. However, when you do, that knowledge quickly pays for the time invested in learning it.