Does the idiom/phrase "place is your swamp" exist or is it worded differently?

So I was talking a bit with a person and a joke came up about collecting treasure in the desert and how there’s only sand, and so I stated "I mean, if your into collecting sand then the desert is your swamp."

If I were to say what this phrase means, then I’d define it as "a place where you belong due to its affinity to your liking and your requirements" or more specifically "a place where you would like to be because it has what you need.")

And he was so confused by this, so I looked it up and could not find anything. Is this an actual phrase people use or is there a different phrase that basically has the same meaning in a sentence but is worded differently?

That aside, any other information regarding this phrase/idiom, any tips regarding the way I wrote or anything I did wrong are much appreciated, thank you for your help.