"You're a romantic. I can already see that the first time I saw you. And you're in love. Nothing is worse than being a romantic and in love. You may look careless and effortless in many things, but you are not. You need to keep in mind that you should always stay who you are. Don't ever change for a person, let alone a guy. Don't trust them too easily, they will leave sweet words in your mouth to make you feel something you actually don't. Men are not to be trusted. Always love a guy who loves you twice as much - even then, they're only meeting you halfway."
A (sort of, edited) piece of advice my (adult, male) religion teacher gave me, randomly, while passing me by after class.