Measure your humanity by more than just yourself. Marcus Aurelius 6.19

Generalizing from the particular works better when we know more particulars: my acquaintance with humanity should be extensive enough to suggest things for me to learn that I don't discover on my own, so that I express & become more than just my most narrow imagination of myself.

Μή, εἴ τι αὐτῷ σοὶ δυσκαταπόνητον, τοῦτο ἀνθρώπῳ ἀδύνατον ὑπολαμβάνειν, ἀλλ’ εἴ τι ἀνθρώπῳ δυνατὸν καὶ οἰκεῖον, τοῦτο καὶ σεαυτῷ ἐφικτὸν νομίζειν.

Don't suppose that something is impossible for mankind just because it is hard for you. Instead, think that you too must be able to grasp a thing commonly possible for other people.