Why was he rude to me at the beginning when we met but is giving me signs of liking me now?

Like what's with the change? He's stuttering and acting awkward in my presence and looks at me even though we barely interacted. I thought he thinks I'm stupid (I made some mistakes at work which pissed him off)? Is this common in men?

Why was he rude to me at the beginning when we met but is giving me signs of liking me now?
Post Opinion