There is no such thing as overreacting.

This word should probably not exist, because overreacting does not really exist, except maybe with actors.

If someone reacts more strongly than I expect to something, it might be because they have stronger feelings and thoughts than I knew about.

Or it could mean that they are reacting not just to the current event (or words, etc.) but that they are reacting to the current thing, plus those similar things that have happened to them in the past.

So the person is reacting properly, if strongly, to the accumulated emotions and thoughts, and maybe traumas, that they have experienced in the past.

To say then that someone is overreacting is incorrect.

I need to be accepting of others, knowing that I do not know their history, feeling, thoughts, traumas. I need to be open and accepting of where people are.

I need to keep this in mind, not just when dealing with others, but when looking at myself and my own reactions to things. If my own reaction is stronger than I would have expected, then it is something that I need to look at. I need to investigate the source and get to know parts of myself that may be hidden. And I need to take the time to look, and to be open and accepting of myself.