I think I read this somewhere on this site, but it's worth repeating. Harken back to the "old" days of ded-rekoning and celestial nav.

On a long haul flight, Navigator requests Captain come left 1 degree to maintain proper course. Captain berates navigator, "damn it man, there's no way one degree is going to make a difference - you can't be that accurate, only give me turns of more than 3 degrees". Navigator sheepishly replies, Yes Sir.

10 minutes later navigator requests captain turn left 8 degrees. Captain replies - Now that's more like it!

10 minutes later navigator requests Captain come right 7 degrees.