People boggle me!

I really don't understand the bird finger. Ok so I accidentally cut you off, honest mistake is it really necessary to flip me off? What does that accomplish, honestly? It's not like I singled you out and said to myself, "Hey I think I'm going to cut that person off....NOW!". Is there something I don't know about this one single finger. Does it do something to me? Let's all be adults and move on.