What do 당신 think my fear is?

It can come in any colour,
It really smells,
Its quite a common fear,
It happens alot if 당신 are 18-30
Nobody likes it,
당신 sometimes do it if 당신 have has a big shock,
Guess what it is,
If 당신 do,
I won't give 당신 a million props,
and I won't add you