Obviously you missed that the default is all inputs set to ANALOG IN.

So if you do not do anything all ports with ADC support are, by default, on Power On set analog inputs!

Even if you don't use ANSELx.

But if you use BOTH ANSEL and ANSELH to set the digital and analog inputs, it is not possible to have analog in on PortB.0 using this:

ANSEL=%00000001
ANSEL=%00000000

PortB.0 will be Digital, either in or out defined by TRIS.

Ioannis