I have the following problem understanding Pauli exclusion principle. Two identical fermions can't share the same quantum state. Two bosons can. Now Cooper pairs are bosons made up from fermions. Everything clear up to this point. Now several Cooper pairs can share the same quantum state, since they are bosons. And now: how do electrons inside particular Cooper pairs consider them different? I mean: if every Cooper pair is identical to any other and all of them are in the same quantum state, then every such Cooper pair is the same quantum state. How do electrons know they belong to different Cooper pairs when all of them are the same? I bet the interactions inside a pair have something to do with it. But how it is mathematically described? How come electrons can tell apart different pairs from inside and still each of them looks the same from outside? My questions also extend to superfluids and all bosons composed of fermions that share the same quantum state.