Odd Perceptions

It is so fascinating to hear people's perception of me. In my mind, I have this set in stone opinion of myself that never wavers, and it's weird to see how people interpret my actions. I'll share some examples.
You are a social butterfly. INCORRECT. I hate being in groups, I hate talking to people I don't know. M discovered this anti-social side of me about a year into our relationship. He says I become "manic" around a group of people, especially new people. Where others clam up in uncomfortable situations, I become the conversation conductor. There can be no awkward silences or pauses, the conversation must move fluidly from one topic to another, and if a topic can't be found I just say crazy random things to make people laugh. It is like watching a train wreck in the form a short girl getting hives. I'm more of a twitchy caterpillar with word seizures than anything else.
You seem like you've worked at (NEW FIRM) for years. Really? Each day feels like a million years, but the fact is I've been there for four months and don't do anything. HR likes me out and about doing administrative things like interviewing, networking, training, probably because of the above social butterly misconception.
You're only 24? You seem older. I hope this is referring to my maturity level rather than potential graying or wrinkles because I don't have a good explanation of why people think this. It may be because I have a 401K, while others in my office who are older than 28 just started contributing to one at my urging. Or the whole savings thing - coworkers are always asking me how I can save so much money each month. These same (single) people live at home, have no school loans, and their parents pay for their car insurance and phone bill, and they don't have enough money for a savings account. Is that normal?? I save 50% of my take home pay - only because I am currently paying off my grad school course and have a big car insurance payment coming up. Astounding.
What are some misconceptions people have about you?
Now I'm off to go write a long post on how to save money during medical school, see you tomorrow!