Knock knock. Who's there? Sew

Sew who? Sew glad you asked, it's a tailor-made joke!

Knock knock. Who's there? Dewey.

Dewey who? Dewey *really* have to endure another pun-ishment this groan-some?

Knock knock. Who's there? Oblivion.

Oblivion who? *everything ceases to exist*

Knock knock. Who's there? Ego.

Ego who? Eggoing to let me in, or is that just a waffle excuse?