Ad,
There are many differences (such as the Filioque or Church governance) which I'm sure wouldn't interest you, but if I had to mention one it would be how we approach the faith. One is cerebral, the other mystical. An RC learns the faith by someone telling them We teach this and that, and he says Yes. The Orthodox learns the faith through participation in the Divine Liturgy and the Mysteries, a revealed faith. That is why, for instance, we have a much deeper theology of iconography.
Essentially doctrinal differences, but as I understand it there are big areas of foundational agreement too – the various Councils for example. I can absolutely see that the narratives of, say, “revelation” make perfect sense to you, but can you see too why someone not steeped in it would find that bewildering?
If, say, I just landed from Mars (as theology-wise I suspect you pretty much think I have) and said, “what’s this revelation stuff, and why do you think "mysticism" is any better a guide to objective truths than just guessing?” what answer would you give me?
Oh, and about those hats by the way…