Also close in sense:
You don´t/can´t change the subject, do you?...
Aah, so you are a one-topic person then?/
You want only to talk about one thing. You only talk about your travels (put the subject you want to refer here - replacing "travels")...
If you want to make a change of subject in a more politely way:
That makes sense, but I’d like to hear more about... (whatever matter you were talking about earlier).
Another softer way: Aah, you are becoming a one-topic person, OR Ahh, it sounds as you are becoming...etc.