I'm not sure when this started but I remember a moment a few years back when I realized this trait for the first time.
Is there a short check I can do to find out more?
In your case, topics like emotional attachment style come to mind. Some people just grow up learning to condition their emotions become more numb... though in some cases it also becomes harder to become excited about things.
This is not to say that this is how you are... since it's not like I actually know you or your childhood, etc. But this is certainly a topic that I'm reminded of when I hear your example, and something like therapy can be an interesting way to dive into this.