Why is it...

...that I always feel like I'm working on my bicycle or doing something for my bicycle. In 1993, I dropped $300 on a Schwinn hybrid and I swear that I cannot remember ever changing a tube or lubing a chain. I swapped out the pedals once. I put centuries on that thing! Now I have a mountain bike commuter that I built up the way that I like it and I'm diagnosing creaks in the cranks and replacing chains annually. Did anyone else ever have a problem free bike? Also, what is this creaking in my cranks this time?