I also want to echo that you may want to consult with a doctor. Assuming you normally drink enough water and regularly, there's several medical reasons why this may be happening.

In my early 20s I started getting a similar experience - turned out my kidneys were slowly shutting down.

I don't want to alarm you though! It seems more likely you just never drink water on a regular basis. A similar analogy would be if you never ate on a schedule and only ate when your body felt starved and then you over-ate to compensate. Probably not the healthiest thing to do though.