I don't know how common this is among trans people, but for many years I spent a lot of time looking for signs that I was not, in fact, trans. And frankly, they are not hard to find. I suspect even most cis people would doubt their gender identity if they had reason to look.
It's the obvious things. The biological differences, the societal pressure to conform. The various alternatives thrown at us - you just have masculine/feminine interests, that doesn't have to mean anything. You're just interested in a surface-level presentation. You're just a pervert. You're just trying to escape responsibility/gain privilege. We really should be dismantling gender roles altogether rather than moving between them. So many excuses for why what we're feeling doesn't mean what we think it means.
But it's also subtle, well-meaning things that get twisted by self-loathing. A trans person telling anecdotes of gendered experiences in their childhood and sure you found a lot of similarities to your own life, but also things that you could not relate to. Their description of dysphoria involves panic attacks and anxiety, but what you are feeling is more akin to a constant sense of hopelessness. They talk about benevolent friends seeing them for who they are and helping them come to terms with it, and no-one has ever seen that in you. At least not exactly like that.
Surely if your experience is so different you can't be trans. It's one of the other things.
And the more trans people I talk to, the more I understand that where we are coming from, what is important to us and where we are going is wildly different. Even for people who want nothing more than to pass as cis the ways in which they realized this and the journey they are taking there has a lot of variance. There's a reason good therapy focuses on what, specifically, would make you happier rather than how many trans boxes you check.
So I think it is fair to want to shy away from responding to gender-nonconformity as a joke but rather take it as a serious expression of identity and be curious about that. I think for someone who is just doing it as an act they will be quick to point that out. But responding with insincerity to a trans person taking their first trembling steps into finding their true selves just adds to the mountain of small excuses keeping them from happiness.















