I don't know that I ever heard any tropes about feminism or feminists before I actually came into contact with the concept of feminism, but once I was introduced to it, and began identifying as a feminist, I sure started to hear them then! Most of them I found laughable, like the accusation of seeking dominion over men, or the "fact" that feminist women are humorless, or the nasty pronouncement (as it was intended, but not received) that I must be a lesbian to call myself a feminist.
Intellectually, I knew the whole "feminists are man-haters" chestnut was bullshit, too, but for Reasons, I found that one a little more difficult to not feel defensive about, particularly because, in my early feminist awakening, I was still busily playing the Exceptional Woman, so I felt obliged to reassure my male friends that I didn't hate men.
That's probably the closest I came to believing/internalizing a trope about feminism/feminists.
Many of my feminist friends, both women and men, did not, however, grow up in the absence of discussion of feminism, but in a space actively and explicitly hostile to feminism/feminists, and had to overcome a lot of internalized negative messaging on their way to identifying as feminists/feminist allies.
So, here's the topic for discussion: What, if any, classic stereotypes about feminism and/or feminists did you once believe? Do you remember the moment(s) in which those stereotypes were forever broken?