Or as my girlfriend likes to describe it, we have "spiky skills." That is, very high in some areas, and very low in other areas.

I work with a six year old who's still learning the most basic skills (like following one-step directions, such as "put your backpack in your cubby"), but he can spell out the full Latin names of various obscure fruits and vegetables from memory in order to find pictures of them online. Although he still has a long way to go with communication skills (he doesn't speak and only recently acquired an AAC device), it's clear he knows a lot more than would be apparent from the outside. Classic "spiky skills."