I don't think it's wildly optimistic, but perhaps we are thinking about it in different ways. I don't think I could teach someone how to implement each data structure in an hour, but I could easily go over maps/queues/stacks/hashtables and tell you when to use each in an hour. I know this because I do that very thing in less than an hour in code reviews.

I do agree that the "stickiness" is iffy, but it usually sticks pretty well. You then have a second problem that can be described as "when you have a hammer, everything is a nail" as they use their new fancy hashtable everywhere.