What should I REALLY know about moving to OBX?
Some of these are repeats of what others posted but I'll add them myself from my own experience.
Rough winters. Especially January to early March. The average temps of the 40ºs are nice until you have 30kts of NNW wind blowing for 5 days straight during a long Nor'Easter.
Making connections. A lot of people come here, not a lot of people stay. This is both in the seasonality and transient nature of the type of work that brings people. The ones that do stay—or were born here—are kind but not always welcoming to make deeper friendships. I think meeting so many people who come and go affects how you interact with new comers. Not to mention there can be an undertone of "well, you're a local sure—but you're not from here". Don't get me wrong. The people of the Outer Banks are great. But it can be hard to make actual "friends".
You really need to enjoy outdoors to enjoy living here. If you're not looking forward to doing stuff in, on, or around the water on a regular basis—you're going to get bored. The people who enjoy living here the most enjoy these types of activities.
Roads flooding. Most people know about the hurricane issues, but depending are the area you reside or need to travel, there can be water salt water on the road during Nor'Easters. This is a much bigger issue on Hatteras than up in town though.
Specialty medical care. Anything beyond basic medical needs you're probably going to have to drive to Elizabeth City, Chesapeake, or Norfolk for.
Shopping. Shipping times are longer out here by a day or so usually. Some places are closed or have limited hours during the winter. And if you buy local you'll be paying more. We don't have cheaper options like Ollies, Big Lots, Aldi, Harbor Freight, etc, for things like other areas do.
edit: I will note that even though OBX can have it's difficulties we enjoy it a ton here. I love the experience it is for my children as they grow up and believe it was a great decision to make the move here. It's hard to beat going to the beach on one's lunch break (if you so choose…) but that type of trade off for the difficulties mentioned above isn't for everyone.