My favorite quotes from Heraclitus:
πολυμαθίη νόον οὐ διδάσκει
Much learning does not teach understanding
ποταμοῖσι τοῖσιν αὐτοῖσιν ἐμϐαίνουσιν, ἕτερα καὶ ἕτερα ὕδατα ἐπιρρεῖ.
Ever-newer waters flow on those who step into the same rivers.
χρὴ γὰρ εὖ μάλα πολλῶν ἴστορας φιλοσόφους ἄνδρας εἶναι
Men that love wisdom must be acquainted with very many things indeed.
τὰ ὄντα ἰέναι τε πάντα καὶ μένειν οὐδέν
All entities move and nothing remains still.
What was scattered gathers.
What was gathered blows apart.
Just as the river where I step is not the same, and is, so I am as I am not.