Never

To be very frank,
seriously,
I have totally no idea about how people could make assertions on "definitely will not"!
I don't mean to play safe,
but come on!
You will be slapping your own mouth when you are caught doing something that you used to say "definitely not"!
I've seen quite a lot of cases that people slapping their own mouth,
I responded to their "definitely will not" assertions by mood,
sometimes I will be teasing them directly by reminding them what they used to say,
but sometimes I will just ignore it .
The point I am trying to make here is,
you will never know what would happen tomorrow,
so,
never say never!