I had one but the wheels fell off
A sarcastic reply, used when you don't understand what the other person is saying (commonly technical).
Frenchie: C'est ville quos muos pume rouge j'aime marsh'mallo
Paul: I had one but the wheels fell off.

or

Person A: All you have to do is remove the hydraulic overhead slip ring so the cam will meet the side flange.
Person B: Yeah, I had one but the wheels fell off.