Why was Santa's little helper feeling depressed?

Because he had low elf-esteem.

Why did the head elf take a course in public speaking?

He wanted to learn how to deliver his *present*-ations more effectively.

Why did Santa always double-check the gift tags?

He didn't want any mis-present-ations.

Why did the Christmas tree go to the doctor?

It was feeling a little knotty and wanted to get to the root of the problem!