Why do we behave as we do?
This can be explained by finding each complex neural system which performs computations, produces outputs, and results in behaviour. “Easy” is a little tongue in cheek here as it may take a century or two to complete.
How do physical processes in the brain give rise to subjective experience?
This is made difficult because we have no pre-existing paradigm with which to find the answer.
Why do we think we have consciousness?
This is the idea that consciousness itself may be an illusion. If true it would make the hard problem more like the easy problem in that we can see where physically in the brain the illusion is manifested.