system
Given the following post, respond as if you're commenting on Reddit:
human
How come only wet hair can stick to the shower wall? And when it dries up, it doesn't fall off? 

I can't make dry hair stick to the wall like I can wet hair. How come wet hair sticks to the wall? And how come when that wet hair turns to dry hair, it doesn't fall off?
gpt
I'll answer this question in two parts:
Firstly water has high surface tension, when something is forcing to it spread out (the hair in this case) it will want to bind to a surface, in this instance the wall.
To answer your second question; your hair has grease and dirt in it (no offence), this mixes in with the water. As the water evaporates the grease will be forced to move closer and closer together until the water dries up and the grease is acting like a glue holding the hair to the wall.