Start From Zero was founded by a Hong Kong local street artist - Dom.
START stands for STreet ART, STencil ART and STicker ART.
He started performing street art from nothing, i.e. "zero: I hope that when someone sees my sticker, they will be like me, start doing street art from "zero".
It can be a slogan for encouraging people when they are unhappy, down or miserable.
He also wants people to remind their friends of this slogan when the same things happen.
Start from Zero