Newton's "..standing on the shoulders of giants..." was a dig at Hook (who was short). It's Isaac being an arrogant jerk, which he was in spades. (Even if he revolutionized thinking in a number of areas.) It's not a statement of humbleness..
I don't know, I heard this interpretation before but honestly the phrase makes sense when interpreted the other way around too, so way not just take the first meaning.
The dig at Hook is a fun knowledge nugget anyway, that silly Isaac. :-p
