Qui tenet anguillam per caudam non habet illam.
(Medieval)

(pron = kwee the-net ahn-gwil-lahm per cow-dahm nohn hah-bet il-lahm)

The one who catches an eel by the tail does not really have it.

Comment: This strikes me as another version of “knowing enough to be dangerous”.
When I was a child, my brother and I got ponies for Christmas one year. We
lived in a rural community in Alabama, and had pasture land as well as woods to
play in. Our ponies had the run of it all, and in short time returned to their
wild state. My father and my uncle felt that they needed to be “broken”, and
so, they set out to “break” them. I’ll never forget watching the two of them
successfully grabbing one of the ponies, only to have her rake the two of them
down the barbed wire fencing. There was a “breaking” that day, but it was not
of the ponies! They remained wild.

I hear a spectrum in this proverb. On the one hand, human study, preparation
and knowledge are all necessary in many fields in order to be competent, in
order to excel, in order to be safe, in order to be just. Knowing enough to
catch an eel by the tail will only get you bitten. On the other hand, humanity
is a part of creation. We do not own it. We are one of the members of a vast
universe that has a place, a role. In some arenas it is not ours to dominate,
but to cooperate. Sometimes, cooperation means standing back and watching the
wild pony run and realizing that the wild is simply beautiful as it is.