Said to me by the man I’m dating. Known him for a few years but we have only recently reconnected.
When I asked him what he meant, he said some people still look young at my age, but I look very mature. 
I am 23, he is nearly 32.
Other strange things he has come out with randomly (which feel like he is trying to put me down) is that although I can drive, I’m not a driver like he is - whatever that even means? I’ve driven longer than him, he doesn’t have have a car anymore.
And the one I actually found rude - I got the highest possible grade for a few university assignments - and he told me ‘it’s good that you can work so hard to get good grades, some people are naturally academically gifted so don’t need such a strong work ethic - I don’t have to revise to do well’ he did no further education beyond a college course, which I don’t think he passed.
I brought up all these things and he pretended to be ignorant and have no idea any of these things were strange or rude. There’s loads more - such as mentioning I have a larger frame than average but it really suits me 
(I’m UK size 10-12)
So my AIBU is - AIBU to think he knows exactly what he’s doing, and I should get rid of him?