Habit Conversion
You usually say the same old stuff, but something totally random gets your brain stuck, making you forget your usual lines. Most of the time, the random thing was just dumb luck.
I was going to say 'I’m not tired!' but my cat jumped on my face and I fell off the couch.
I was about to say 'I love this song!' but my phone started playing a baby crying.
I was going to say 'I’m the best!' but my neighbor’s dog started barking at me like I was a thief.