What does it mean by saying "I'm with you, Cheech"?

[Joeyy]

Rachel: What's up?
Phoebe: (whispers) In the cab, on the way over, Steve blazed up a doobie.
Rachel: What?
Phoebe: Smoked a joint? You know, lit a bone? Weed? Hemp? Ganja?
Rachel: OK, OK. I'm with you, Cheech. OK.

——Friends S01E15

 

[emsr2d2]

"I'm with you" means "I understand".
Cheech is one of the main characters in the Cheech and Chong films - they smoked a lot of pot in those films, I believe. Because Phoebe has shown that she knows a lot of terminology for marijuana, Rachel jokingly calls her Cheech.

 

[SoothingDave]

It's a fact. Cheech and Chong's genre of film was that of the stoner.