I'm going to interrupt a conversation to try and make it to my train ride
Would you try to be more polite about how you do this?
No, I need to go because I promised my parents.
I understand it's bad to run late, but you should be more polite in how you interrupt. Wait for them to take a pause or when it's your turn to talk, or else speaking right when they are shows you are impatient and careless.
I don't want to talk until my thoughts are finished.
I get that, just remember to be mindful on how you go about things.