I use to get that all the time because I have ADHD and one of the symptoms is a expressionless look or negative facial features even when im jumping up and down inside im so happy I look negative it sucks what people think about me but this is how God made me and thats how it is like it or not you guys are lucky you actually smile when your happy. Actually maybe it is' nt all bad when someone like your talking about see's me coming they just turn around and walk away very fast.