I've been playing on my current drum kit for 10 years now. In that time, I've broken more drum sticks than I care to remember, worn out numerous sets of drum heads, split several knuckles, and - most painfully - cracked a few cymbals. All of which is pretty standard fare for drumming. Granted, I probably played on all of those listed items longer than I should have after their integrity was compromised, but hey, cymbals aren't cheap and I've only got the one set of knuckles.
Particularly with drum heads, it's really a good idea to change them more often than you probably think you should. Constantly being stretched over the shell and receiving what would be termed assault with a weapon if you hit a person in the same manner, the things just wear out. When that happens, obviously, the sound quality drops.
I remember in the room I took drum lessons in when I was young, my instructor had an old beat up head with a message written in black permanent marker that read, "Here's an idea, change your heads BEFORE they break." For the most part, I've taken that poignant advice throughout my drumming career. Even when I play on heads too long, I consciously know that I need to change them before I record or do anything important.
What I haven't considered is the resonant heads on the bottom of my drums. I'm always careful not to damage them when I move my kit and I don't do anything silly like swapping them out with the batter heads in a pinch, but it took me getting a hole in the resonant head on my snare to think about this a little harder and to realize that those heads have been through a lot of strain over 10 years constantly being stretched out and rattled around.
Through looking around at my options for snare side heads - I went with an Evans 500 to match with the power center batter head that I use - I realized how much tone I'm missing out on BY STILL HAVING THE STOCK RESONANT HEADS ON MY DRUMS. Not only have I never changed them, but they're factory stock! How in the world did I miss this?
The bright side to this is that you don't have to make my mistakes and I'm about to experience an entirely new side to my kit once I slap some new resonant heads on there and get everybody nice and tuned up. So do yourself and your drums a favor, and change out those heads.