(one) could go (on) all day (about something)

(one) could go (on) all day (about something)

One could continue talking about some topic for a long time. Sorry, I could go all day about model trains, so let me know if I'm boring you. Look, we could go on all day, but the point is that you screwed this project up, and now we need to find a way to fix things.
See also: all, could, go
Farlex Dictionary of Idioms.
See also:
  • a one-horse town
  • one-horse town
  • burg
  • a drag
  • drag
  • carry (someone or something) along with (someone or something)
  • carry along
  • chestnut
  • (old) chestnut
  • an old chestnut