This is a collection of sentences, or behaviors, that immediately raise a red flag in my mind. Some of them are not necessarily bad, but in my experience, they have been associated with stupid people.
Ample use of emoticons - things like :( or :D - in writing: almost always it’s someone silly.
Ample use of exclamation signs: nobody can be that excited about things. I find it dishonest.
“I’m a realist”: what they usually want to say is “I’m more intelligent than you”. Unless, they do believe there is one reality, and they grasp it, in which case they’re deluded.
“I see shades of gray where you see black and white”: I almost always hear this from cowards.
“I would have done that for you”: said when you refuse to do something they ask. Maybe they’re honest about that, but would they be willing to do for you what YOU want done? No? I didn’t think so…
“You and I can understand this, but most people can’t”: toxic, run away.
Apologizing profusely: people who really mean it, apologize only once or twice, then fix their behavior. I find serial apologizers dishonest.
Great gratitude: same as above. Honest people say thanks once or twice, then surprise you returning the favor at a future time.