Low oil pressure makes me nervous

I see many comments here regarding the accuracy of the factory oil pressure gauge, don't know why ... the gauge is reading fine and that is the reason for the concern---low oil pressure. Now that I arrived here in Mill Valley along the coast, the mornings are cool in August and the 40 Wt. is reading between the second and third graduation at idle when first starting up. When fully warm at idle, the pressure drops all the way down to halfway between the zero and the first graduation. And that does not bother me, but climbing the grade the other day at "full speed" with the same oil pressure as hot idle pressure is what made me nervous and the reason I started this thread in the first place.