the problem with that is that they can be totally different than who they truly are. the longer you spend imagining how this person sounds or acts, the more of a rude awakening you may face when you realize you were completely off the mark.
when people already know you, they understand your humor. they understand if you say “everyone must die”, they will think “oh this is mike just being mike”. they won’t call the police or forever brand you as “mentally unstable” because they already know you! people who just met you, may not get that off hand. you can easily rub someone the wrong way or turn them 