Who are you? Who are you with your friends, with your family, at work, on dates and in a relationship? Are you the same person or do you have different personas depending upon who you’re around? If you’re dating someone and begin introducing them to your family, friends and coworkers are they going to recognize you and your personality?
Everyone is on their best behavior during the first few dates with someone new, that’s understandable and acceptable, but if you make a complete 180 once you get serious or are around other people then you aren’t being real, and you’re not being fair to yourself or your date. Don’t be fake, that requires far too much effort, and you don’t want someone who likes you for who you are pretending to be.