Agamon
Adventurer
As for the specific case of knowledge checks, a typical DM response might be to dictate automatic failure for anyone who didn't have a reasonable chance of knowing the answer. For a Dwarven history check, everyone would automatically fail, unless the character is a dwarf and/or the character has History proficiency.
I like to cut the typical DM a little more slack in understanding how knowledge works. One doesn't have to be a master of X to maybe know a tidbit or two about X. However, a master of X will indeed know a whole lot about X, and shouldn't require a roll in regards to non-esoteric information about X.