Can a younger person really manipulate an older person?

In this case, the age differences were 19 and 25. both women. When I was 25 I briefly dated someone 19 who would insult, harass and threaten me and more and I always excused it as immaturity until now (a few years later) they have the same behavior and my therapist described it as abuse. I'm still unsure though. I was always hyperaware of my own behavior and of not doing anything that would make her uncomfortable but I excused hers with the age difference And I guess I kind of cringe at the fact I'm so easily manipulated at my age but yeah