Newton was not a nice person. He had a big ego, always tried
to make him look better than his peers. He got real nasty
in his long standing argument with Leibnitz, (Newton's "fluxions"
vs Leibnitz' derivates), dividing the Western scientists
into two camps. Newton also made his Principae (spelling?)
hard to read, on purpose
. He didn't want to be bothered
by remarks and questions from "lesser scientists".
Does that mean Newton didn't understand his stuff? Or that
he wasn't a first class scientists? I don't think so.