I've Got The T-shirt Edit Meaning

1.

Alternative to "been there, done that", often accompanied by "I've got the mug".

Idiomatic expression used to show that something is really not that interesting as you've already done it before and so have many others.

Excited kid: "Have you ever been to Disneyland?"

Bratty, patronising older kid: "been there done that, I've got the T-shirt and I've got the mug".

See tshirt, mug, t-shirt