I agree - there are lots of questions that are highly detailed in nature, that unless you happen to work with a LOT, you're going to have trouble remembering. It's very good in my mind, especially since it DOES tend to keep us humble....

Throwing little interesting tidbits your way, forcing some amount of research, seeing something odd/new that might end up being useful - all really good stuff...

And the point is - at your job, you're going to implement things you're familiar with, and if you're not 100% confident, you will be double-checking the answer before throwing something out there. No one said you'd need to implement EVERY feature included in SQL server: if you only use 25% of the features, but you can do everything you need to with that 25%, who cares? You got the job done.