system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: "Hydrogen is an odorless colorless gas which, given enough time, will start to think about itself."

I just read this on an askreddit thread.
... what?
gpt
long story short hydrogen is what most main sequence stars are predominantly made of (followed by the heavier elements in decreasing order of probability).

When hydrogen fuses to make heavier elements it gives off light (energy) which we see/feel.  Eventually all (most) of the hydrogen is fused and the star begins to fuse heavier and heavier elements.  Eventually it cannot fuse anymore (Iron) and cannot fight back against gravity.  When this happens the star explodes littering space with all sorts of elements which eventually gather and form other stars, planets, junk, andy dick, etc...

Our Sun for instance is predominantly Hydrogen but actually contains various heavier elements that a "pure hydrogen" star wouldn't have at this point.  Very likely our solar system is the product of other stars going nova.