Having the details and characteristics of the b-trees(among other things) in memory allows you to consider them as possible solutions to a problem you are facing. If you dont know the details you would probably not know they are a good fit for a particular problem. The more detailed knowledge you have in your memory the bigger your possible solution set will be, thus, you will have a better chance at solving a particular problem.
I think Google is not looking for people that can follow specs(although thats valuable also) but people that can come up with brilliant solutions to hard problems.
I think Google is not looking for people that can follow specs(although thats valuable also) but people that can come up with brilliant solutions to hard problems.