I've heard many examples
..."all musicians smoke pot"...no, not at all, probably not even a third or half...and so what if they do?
..."so-and-so was on drugs so they probably still are"...no, many people quit and quite possibly are better people with perhaps better character than you!
..."that woman's alone so she most certainly must be lonely"...not necessarily...in fact she is free, strong, independent and likely happier than she's ever been before!
..."that person has had various negative problems and struggles, and they won't be dependable and aren't worthy"...untrue, people change their lives through their actions, renewed efforts, and may be the most worthwhile person you ever meet!