When I interview for jobs, I open up to any of the possible things in my background, of which it will take me perhaps 2 weeks to get back up to speed. But I am not going to take that 2 weeks for each job I interview for.
I have trained my brain to learn things, and discard them keeping only the current tasks in memory. The rest I know how to obtain again.
This means that I get asked questions I know that I've done repeatedly in the past, but can only vaguely explain without a refresher.
To the interviewer, this means I am underqualified at best, and at worst, lying about my past skills.
A lovely example of this during the process was that I was asked a fairly basic SQL question that I failed to explain when I had just landed from my second flight of the day. I didn't get the presales role for working with the database. (non referral job.)
However, I did get offered a job working on development for that database, as well as product management for the database.
So I couldn't get a presales role, that I've done in my past, because I couldn't answer a fairly basic sql question. I knew exactly how to answer it, the venn diagram of sql joins, a half second google, but in an interview, I blanked on the answer.
That is indicative of my experience with non-referral positions. I've given training on sql joins a good 30 times in my life, and couldn't explain the join in an interview.
Just the way it goes for me, thankfully it's not actually impactful in my life.
I've been interviewing a lot of developers lately, and while I'm fairly happy with my process (I've managed to avoid bad hires so far), I always have to wonder if I'm turning down people I shouldn't.