Most Helpful Girl
If he's your boyfriend then he better be caring about you. It's common for a guy to remember little details about you and it does mean he cares/likes you. My boyfriend doesn't know my clothing size because I haven't told him but he does know details you have mentioned, like favorite color, candy and my favorite foods. Your boyfriend cares about you
Most Helpful Guy
He cared enough to pay attention to those things. That doesn't mean he'll be proposing soon, it means he's a caring person.