"The farthest" vs. "the furthest"
Hello everybody! I need your help again guys!
I know that both "farthest" and "furthest" and superlative degrees of the word "far" and I completely understand that there are different. "Farthest" is used to denote physical distances directly, but "furthest" is used to denote distances in a non-physical or an abstract way. Okay, it's clean. But, what about this sentence?
Example:
"I commute the furthest out of all my colleagues".
I know that this sentence is grammatically correct, but could someone explain to me why. We're about a physical distance and not an abstract one. If yes, why do we say "furthest" in this example?
Thank you for your comments!:)