A: Why are you cutting into the wall?

B: I bought a new air conditioning unit.

A: I don't think that's how you install it!

B: Have you ever installed one before?

A: No, but that still looks wrong.

B: I think I know what I'm doing.

A: I see water pipes behind that wall.

B: I don't think that's good for the air conditioner.

A: I don't think so, either.

B: Will you call some professionals now?

A: I guess that's the best thing to do.

B: You should have done so from the beginning!