Let me really get people going.
If you define Nz as your g measurement, then when your aircraft is pitched up in level flight near stall speed, your z axis is inclined to the vertical, perhaps 15 degrees.
In that case, your Nz will be less than 1 in level flight (before you start falling out of the sky), probably somewhere around .96 g.
That force you feel on your back accounts for the rest of the gravitational field.