Hastings and Poirot in “Unfinished Business”

Hastings

[The car]'s been running like a bird since I've fitted the new gaskets.

Poirot

Birds do not run, Hastings. When you were little, you should have paid more attention to your lessons in biology.

Hastings

You're really in a bad way, aren't you?

Poirot

Well, my friend, as one approaches the end, one begins to see life as it truly is.