What is the difference between "cuckoo","nutty", and "obtuse" ?

For instance:
He is too cuckoo/nutty/obtuse to take a hint.

Thank you very much for reading : )

Question

What is the difference between "cuckoo","nutty", and "obtuse" ?

For instance:  
  He is too cuckoo/nutty/obtuse to take a hint.

Thank you very much for reading : )

Answer

Cuckoo and nutty usually mean “crazy”. Obtuse means “insensitive”. To me, none of these words fit well into the sentence that well. I would say “oblivious” or “clueless” works better.

Answer

In (British) English I'd say 'obtuse' is a quite formal word meaning 'slow to understand something' (= stupid). The sentence seems awkward.