"Your mother will cry and ask you why you did not become a real doctor."
I don't think it is true that "when you are a clinical psychologist people always think that you are crazy, so you always have to be extra nice so people don't think you're crazy." In my experience, it is more the case that when you are a clinical psychologist, people you meet outside of work worry that you are going to detect (or have already detected) just how crazy they really are. Most people are aware (to varying degrees) that they are not quite "normal," and they spend a lot of time and energy trying to conceal this from others. Clinical psychologists are fully aware that no one is as normal as they appear to be and that everyone has aspects that are just plain weird. Other people realize that they themselves are weird, and they mistakenly believe that everyone else is normal.