It depends on how it is used.
I suppose not but I'm not long distancing myself from them.
No one is entirely arrogant so it isn't entirely wasted.
I don't even understand that statement.
Ah, ok, I get it now.
Well they still have use of whatever knowledge they have, so even though they don't share it they still use it, hence the knowledge they have has some use and isn't wasted. I guess.
I wouldn't ever consider knowledge "wasted."