Exactly. You don't use it, you lose it. That doesn't mean you don't have the capacity to reacquire it in a short period should you need it again. Most humans are not encyclopedias.

I can describe for you in detail the different index types on MySQL and Postgres, and go into when/why you would use each. But it's been so long since I crafted a complex join by hand I would definitely have to google it. However I don't doubt that I could write the query in a short time. One of the most realistic interviews I ever had, they gave me a laptop and allowed me to google during my answer. I took the job.