iPod "hard reset"?...

Anyone here have to do this with your iPod before? Mine died today with plenty of charge still on it and it wouldn't work at all. One of my co-workers said this happened to them also and told me to hold the menu button and center button down at the same time for a few seconds and that will "hard reset" it. It worked! But now I'm wondering how often that's supposed to happen, and does it mean something else might be wrong with it? Or is that just something it has to do every now and then? lol