It's definitely not stupid. It's a nice hope to have. And no one knows what comes after so why not hold onto that if it's something that helps you navigate this life in a positive manner. It's literally not hurting anyone.
Personally, I don't believe that anything comes after this life and that our consciousness is nothing more than an evolutionary trait that hominids developed to gain an advantage for survival. Therefore I have to keep my momentum going to make this life and whatever time so have left in it something that is worth enduring and enjoying. Grieving the life we didnt get to have when its appropriate, but recognizing that no one gets to have exactly the life that they want. At the same time, transitioning gives us an incredible opportunity to right some of those wrongs, perhaps more so than most cis-people get. In that way, I view transitioning, with all of its peaks and pitfalls, as an incredible gift. But I've also had an incredibly priveledged transition so I understand if other folks don't view it that way.