It's true you make money when you sell but I usually compare the price/ worth of bitcoin with dollars. And there is always a feeling that your coin is appreciating.
As for my emotion I was a new bitcoin holder and gradually I became used to the price situation.
I am a much older Bitcoin holder in relation to you (not that old as there are those that have been here since the early 2010s), and I still get excited a bit when here is a market pump, even though I have no plan of selling.
About your emotion, you would never actually become immune to the market changes, or at least, I haven't. But you would develop a lot of insensitivity to it and would not react in anyway.