So, let's share things that you think someone might know about you that is often incorrect. Here are two examples of my own.
1) I have a great sense of humor--I LOVE to laugh. As for my own attempts at humor, it's sometimes difficult for others to understand as it tends to be rather abstract at times.
2) Despite being one to actively participate in social situations, I actually prefer solitude. A company I worked for in the past had all of it's employees take the Myers-Briggs Type Indicator (personality) test. Before the results were presented, people were tasked (as a part of the exercise) to predict the attributes of others. EVERYONE estimated I was very extroverted, when in fact my scores were at the other end of the spectrum.
So, what about you would surprise others...?