“Relative Forcefulness-of-personality” is variable to be aware of.
“Suddenly having to defend boundaries you didn’t expect to have to” is a particular way that it can be difficult/scary interacting with someone more forceful than you. (Corollary: it’s scarier to interact with forceful people who do a lot of unpredictable things)
“Forcefully telling people how they think” can feel particularly violating, to somewho is less self-assured, because it can leave them doubting their sanity, and undermining their ability to figure out what they want.
I’d like to point out that of these three things, #3 is one (and, note, the only one) which is traditionally frowned upon, according to commonly accepted rules of conversational conduct, independently of any views about how “forceful” one ought to be, etc. This seems to me to be instructive. (We have many words/phrases for it, too: “Bulverism”, “psychoanalyzing your conversation partner”, etc. These are not laudatory terms!)
I’d like to point out that of these three things, #3 is one (and, note, the only one) which is traditionally frowned upon, according to commonly accepted rules of conversational conduct, independently of any views about how “forceful” one ought to be, etc. This seems to me to be instructive. (We have many words/phrases for it, too: “Bulverism”, “psychoanalyzing your conversation partner”, etc. These are not laudatory terms!)