Moods

I have an issue that I wonder if I am the only person who notices this and doesn't like it. I have a problem with people assuming they know what mood I am in. At the last job I had, I worked with a man who would walk into the office all the time and say "Smile! It's not that bad!" 9 times out of 10 I would be in a totally fine, neutral mood, and was just focusing on my work. But the fact that he said that, put me in a bad mood and I would want to punch him in the face. Just because I was not smiling so hard hard my teeth wanted to come out of my head meant I was in a bad mood?

I now work with another woman (new job) who I actually love to death and consider her a good friend. She, however, is an addictive personality and sees the world in black and white. I am positive those two personality traits are related. Earlier this week I walked into the break room and busted out into some song, totally out of tune, just being an idiot. She laughed really hard and said "you are in a way better mood than you were yesterday." I was like, what? "Actually, yesterday i felt totally fine."
"No, yesterday you didn't care about anything." She said.
I explained to her that I am a laid-back person and there are some days I just don't have a strong opinion about anything, but that doesn't mean I am in a bad mood. I also proceeded to let her know she is way over-sensitive to the moods of others, because this is not the first time SHE has let ME know what mood I was in. But again, since she is a Black/White person, she always has an opinion.
I am more shades of gray than that. I can be tired, neutral, happy, sleepy, or just content and laid-back, all without feeling like I am in a bad mood. I am not just good mood/bad mood, and I do not like it when other people assume they know my mood. If you want to know my mood, ask me. Anyone else ever notice this about themselves?