When you are grown-up and very lonely, you'll understand.
5 seconds sound clip from the Addams Family Values movie soundboard.
You can hear this line at 00:48:45 in the Blu-ray version of the movie.
Quote context
[...]
- Next!
- Dear Wednesday and Pugsley, I love you dearly, but I can never see you again.
- When you are grown-up and very lonely, you'll understand.
- Go!
(Bird Squawks and falls from the sky)
[...]