Christmas. He absolutely loves the holiday, and while you don't have to enjoy it quite as much, a 'bah humbug' attitude will certainly not endear you to him.Compliments. Especially on things that he's not often recognized for-his intelligence is something he's well aware of, having coasted through school and wrecking standardized tests, but things like his appearance, even if he doesn't think much of it, or his thoughtfullness.Cooking. Make him something he likes, something you know he likes, and make it for him.They all start with 'c' so far, perhaps I should try to make a theme of that. Ah, of course, caring. Remind him that you care about him, that he matters to you. Sometimes he'll forget that people do, and even if you're not one of the one's he's thinking might not, reassurance is good.Cerebrality. Be cerebral in some fashion, doesn't necessarily what, doesn't necessarily matter how, as long as it's outside of the physical realm. Intelligence specifically is nice, of course, and an attractive trait to him-but energy even more so.Challenge. Be a challenge in some way, be competitive, as long as you can find the right line. He'll love it.Conviction. Care about whatever it is you do with as much fervence as he does. it might cause some debate (see: 'challenge,') but overall it will certainly help things.Commitment. He knows that it's an outdated tradition, especially with some of the contexts it can carry, but he likes feeling, emotionally, like to a degree you belong to him-and don't worry, you can bet he'll belong to you all the same.