> If it's only an odd-even difference, why are composite bosons (like, whole atoms) so more.. exotic than composite fermions?
> That is, why do atoms normally obey the Pauli exclusion principle?
Whole atoms can be fermions (the Wikipedia article gives the example of ³He), and the Pauli exclusion principle applies to fermions within a given quantum system, not to bosons (though sometimes the quantum system itself is a composite boson, though it could also be a composite fermion—the most common set of systems in which it is discussed, atoms, can be either.)
> That is, why do atoms normally obey the Pauli exclusion principle?
Whole atoms can be fermions (the Wikipedia article gives the example of ³He), and the Pauli exclusion principle applies to fermions within a given quantum system, not to bosons (though sometimes the quantum system itself is a composite boson, though it could also be a composite fermion—the most common set of systems in which it is discussed, atoms, can be either.)