proverb/ki tʁo.p‿ɑ̃.bʁas ma.l‿e.tʁɛ̃/
grasp all, lose all; don't spread yourself thin; don't become a jack of all trades, master of none
Literally, “he who embraces too much, clasps poorly”. From Aesop's fable The Goose that Laid the Golden Eggs. Compare Italian chi troppo vuole nulla stringe and Spanish quien mucho abarca, poco aprieta, Hungarian aki sokat markol, keveset fog.