Especially if a new one, pain is undoubtedly a 'warning signal from the body' which is a succinct metaphor we all understand and has a clear meaning. If you don't know why or from whence the pain, check it out. It may be one of those things or perhaps not.
The previous commenter appears to argue that you need to diagnose every headache, which sounds absurd to me.
Occasionally I have a headache. Not frequently, and I don't necessarily know why. These things just happen. I take a painkiller, and problem solved. I've been seen by doctors over the years for physicals or other reasons, and there's no indication of any underlying medical condition. An occasional headache is not an indicator of something more serious, and the painkiller is not "masking" a larger problem.
The same goes for random muscle aches. They're infrequent, but they can happen, for whatever reason, and there's no reason to panic or to suffer when you can just make them go away.
I don't think I'm unusual here. As far as I've heard, random, infrequent headaches or other aches are extremely common.
Moreover, there are pains that we know the cause: for example, I experience a bump or a cut. My body continues to annoy me with pain unnecessarily. Yes, I'm healing, I'm well aware of that. I just need my body to STFU with the pain and stop reminding me of it.
Thank you, I share this sentiment but couldn’t quite put it into words. Sometimes it isn’t that deep.