Yeah, sadly I have had a similar experience where when I hang around people that are homophobic and their thoughts seep into my brain. I wonder "Am i just and a$$hole doing this for attention" or "it seems people are just making up new genders to feel special". I don't really think those things deep down in my heart, but I can't help be scared how quickly those thoughts can be planted into my brain. To answer your question, yes, it is normal to sometimes have those thoughts sneak their way into your brain. I don't know how to get rid of them, but I know that as long as they don't deep root themselves into your beliefs, then you will be okay.