The curious incident of the trans feelings
There's an ugly bit of misinformation going around the Internet, that feelings of gender discomfort always get worse with age. I discovered it the other day in the comments to a New York Tines "Ethicist"column responding to an older trans person. The first comment was by a post-transition woman named Zoe Brain: "Gender Dysphoria varies in intensity, and is also progressive."
It was echoed by another woman, Julie C. from Bala Cynwyd: "Trans is progressive, getting worse as the trans person gets older."
The gist of this argument is that even if you're not one of the "transition or die" trans people, if you don't transition now you'll eventually find yourself in that category. There's also an idea (which I generally agree with) that if you're going to transition the earlier the better. Put the two together, and you get an argument that every trans person should transition as soon as possible.
(I’m still not sure how you get from there to “anyone who doesn’t want to transition must not be trans,” but we can deal with that at some other point.)
For some people, feelings of gender discomfort and the desire to be the other gender definitely do get stronger over time. I've heard this from many trans people, and I don't want to discount their experiences. But it's not necessarily true, and it's not automatically true.
Again we come back to the principle that no one really knows what's going on with trans people, and no one will know until we get some kind of representative sample. Generalizations with "all" and "always" are simply not appropriate.
I personally find that my discomfort with being a man, and my desire to be a woman, are not even perfectly correlated with each other, much less constant over time. They both have their ups and downs, and I can connect some of those ups and downs to particular circumstances in my life, but not all of them. Brain and "Julie C." are right in that both feelings keep coming back, even after thirty years or so, but she's wrong in that on average they haven't gotten more intense or more frequent.
This is again the problem of negative evidence: we can see that for some trans people it gets harder over time, but we don't necessarily notice that for other people it doesn't get harder. For every person who transitions or commits suicide, or even hangs on in quiet desperation, there may be one, or many, who lead relatively happy lives without transitioning, until they die. We just don't know.
What we do know is that there are some people like me, for whom it hasn't gotten harder. And that's the thing about generalizations: they can be invalidated by even one counterexample.