system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why can't we just "make" water?

What conditions need to be met in order for 2 Hydrogen atoms to bond with an Oxygen atom to make a water molecule?

 Why can't we just pull Hydrogen and Oxygen from the atmosphere and create drinking water?
gpt
Hydrogen bonds very easily, and so it is relatively rare to find hydrogen just floating around the air, minding its own business.  On the other hand, water vapor is a fairly common component of the air, and in most places it is easy to harvest.  

TL;DR it's easier to find water than elemental hydrogen.