Φαίνεται δὲ ἐπὶ τῶν Ἡροδότου χρόνων γενόμενος, εἴ γε ὁ μὲν Ἡρόδοτος μέμνηται τῆς Θηβαίων ἐσβολῆς ἐς τὴν Πλάταιαν, περὶ ἧς ἱστορεῖ Θουκυδίδης ἐν τῇ δευτέρᾳ. λέγεται δέ τι καὶ τοιοῦτον, ὥς ποτε τοῦ Ἡροδότου τὰς ἰδίας ἱστορίας ἐπιδεικνυμένου παρὼν τῇ ἀκροάσει Θουκυδίδης καὶ ἀκούσας ἐδάκρυσεν· ἔπειτά φασι τὸν Ἡρόδοτον τοῦτο θεασάμενον εἰπεῖν αὐτοῦ πρὸς τὸν πατέρα τὸν Ὄλορον· “ὦ Ὄλορε, ὀργᾷ ἡ φύσις τοῦ υἱοῦ σου πρὸς μαθήματα.”
(Marcellinus, Bios Thoukudidou 54)
He seems to have come to be in the time of Herodotus, if indeed Herodotus makes mention of the attack of the Thebans into Plataea, concerning which history Thucydides narrates in the second book. And so it is said, that once when Herodotus was making a display of his own history, Thucydides was present at the recital and, hearing it, wept. Thereupon, they say, Herodotus noticing, said to Olorus the father of Thucydides, “O Olorus, truly the nature of your son is violently bent toward learning.” (tr. Timothy Burns)
Crambe Repetita 