system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do scientists look for water or organic compounds when looking for extraterrestrial life forms? Wouldn't it be possible that ET life could arise in completely unimaginable circumstances?

I understand that life on earth is composed mainly of organic compounds, and that life is teeming in water, which is itself a large part of all of us.

BUT, that's what we know about life on earth. Who can say that life outside of earth has to conform to the same rules that apply on earth? Why can't intelligent beings arise from inorganic compounds, or compounds that we don't know exist? 

Wouldn't this type of search be too narrow-minded?
gpt
The problem with that is that, by definition, we don't know what unimaginable life would look like, so we wouldn't know how to find it.  We do know what at least some examples of carbon based life are so we spend our time looking for things like that because that's our only option.