RPGMemes

I don't think I've ever needed more information than character level and a vague sense of whether that character/player is more or less effective in combat/social encounters than usual to make them. I definitely don't need to worry about whether they've got expertise in history, that's something they can bring up when I ask them for a history check

Throwing whatever you please at them. It's fair because they're informed of the risks and given opportunities to adjust their plans.

Just because I have a sense of what modifiers are and might check during encounter building doesn't mean I have them all memorized. That's genuinely like over a hundred numbers to have memorized. Plus I can look at a sheet while building an encounter and not waste anyone's time.