So when you look at something like Reddit and think "I wish I could think of an idea like that," remember: ideas like that are all around you. But you ignore them because they look wrong.
Reading PG's essays makes me very happy. Quoting again:
Here it is: I like to find (a) simple solutions (b) to overlooked problems (c) that actually need to be solved, and (d) deliver them as informally as possible, (e) starting with a very crude version 1, then (f) iterating rapidly.
So when you look at something like Reddit and think "I wish I could think of an idea like that," remember: ideas like that are all around you. But you ignore them because they look wrong.