A term used to describe someone who knows a lot about many things, but, with the second
tag "master of none" added it transforms into a derogatory phrase meant to emphasize how mastery of
one skill is important for deeper
knowledge.
However, one, oft forgotten
tag is the third one: "is oftentimes better than a master of one". Instantly, the term reverses meaning, symbolizing how a person who knows a lot about many things that integrates their skills allows them to surpass even a master of one.
Interesting phrase, nonetheless.
"Man, Tom knows a lot! He's a jack of all trades,
aint he?"
"Yeah, but he probably doesn't
know a lot about specifics. You know how it goes: Jack of all trades, master of
none."
"Jack of all trades, master of one, is oftentimes better than master of one, man. Tom's pretty smart."