seen one, seen them all

Idioms  

1. One example suffices, as in I'm afraid I don't care for home movies—seen one, seen them all. This world-weary expression was first recorded in 1811. A newer idiom expressing a very similar view is been there, done that, indicating that it is boring to repeat an experience once it has lost its novelty. For example, No, I don't want to climb Mount Washington; been there, done that. This idiom was first recorded in Australia in 1983 and was popularized in America in the 1990s through a widely aired commercial for a soft drink.

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Example Sentences

“Even for many hard-core dino fans, sauropods are kind of ‘seen one, seen them all,’” Lamanna says.

From National Geographic

I thought I'd fallen out of love with eco homesteads – they had started to take on a "seen one, seen them all" quality – but then I came across architect Torsten Ottesjö's Hus-1 eco lodge.

From The Guardian

A public reading by Morgan might involve poems such as The Loch Ness Monster's Song, with its sensitive rendering of the voice of the world's loneliest beast; The Clone Poem, based on the conceit "when you've seen one you've seen them all seen them all seen one seen them all all all all"; or French Persian Cats Having a Ball – "chat / shah shah / chat / chat shah cha ha", reprised in rolling combinations.

From The Guardian