I think you misunderstand the concept of evidence, particularly empirical evidence.
I identify with your question. A friend recently asked me why I identify as bi. I answered that it’s based on sincere introspection and my attempts to understand who I am and where my attractions lie. I don’t need to prove anything to friends or myself, I just want to understand myself the best way I can. And I also do aspire to seeing myself without a specific label, but I find that pretty tough to do.
I would have commented on it too if I saw you, with a smile and maybe a high five :)
I’ve got the best fucking attorneys