system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are we so fixated on finding water on other planets, as a sign of life? Is it not possible that other life forms would function without water as we know it?

I just find that we are constantly seeking water when we discover other planets, because it would imply that the planet could sustain life. Is this just us saying it could sustain our lives? 

I just think it a bit myopic to believe that the only life out there must require water for survival.
gpt
It's *possible*, but life probably needs some liquid medium to do chemistry in and water is by far the most common and convenient.

Some planets likely have seas of other liquids like methane and ethane (Like Saturn's moon Titan) but these liquids present some problems that may be difficult for complex biochemistry to solve.

Water also gets the top spot because we have to look for something.  We would have no idea how to start looking for the bio signatures of rock men with lava blood.