hydration nutrition question

This is kind of a question for you serious runners.  By serious, I mean you guys who go out and bust to finish fast and not just finish.

Over the past year of my run training, I haven't been following "proper" hydration and nutrition stradegy during the run.  Any normal run i do that is 13 miles or less, I don't carry anything.  I don't drink or eat during the run.  On the longer stuff, I do pack food and water though.  Before and after, I do follow proper hydration and nutrition stradegy, however.

Is this a bad thing?  During these runs, I have never felt like this has hindered me and all of these runs are around 2 hours or less.  The half I ran yesterday really made me start thinking about this.  During the run, the only thing I had to drink was one splash at mile 4 that was big enough to wet my mouth.  I didn't eat anything before or during.  It was the fastest I've ever run that distance (even though I've only ran twice in the past 2 months) and I didn't feel like my performace was hindered by my lack of nutrition or hydration.  In fact, I was pushing at a level hard enough that I think having something in my stomach would have done more harm then good.  At the few races I've jockstrapped (some 15k's), it always seems that the FOP runners just blow through the water stops too, so I'm not the only one that does this.

So.....is this absolutly horrible?  should I concentrate on drinking more during my running to get my stomach used to it? Does it matter that when I'm doing base runs, I'm staying in zone 2, but I'm racing in zone 3 and 4?