That&#x27;s reasonable, but I&#x27;d like to share an experience I had interviewing a long time back.<p>I&#x27;d been writing lots of mathematically intensive code for building and solving large scale linear programs for about a year, and I interviewed at a job that was doing lots of math-ish business analysis.  Code would certainly be written.<p>I was incredibly busy, and mainly spent my interview prep on math I thought would be relevant, though I really didn&#x27;t adequately prep for the interview.<p>One of my interview questions involved some simple (really, I must be honest there, it was simple) recursive tree traversal.  I blew it, and I&#x27;m pretty sure this is why they didn&#x27;t hire me.<p>Six months later, I had to use quite a bit of tree traversal to model a series of conditions that had to occur in several possible patterns for a manufacturing system.  Because there were various combinations of events that would &quot;pass&quot;, I used trees to model the system, and I needed to recursively determine, in the event that the system didn&#x27;t pass, what possible paths (including the least cost path) existed to bring the system into compliance.<p>I picked up my old reference books, reviewed for a couple days, and started writing code.  As I did this, I started to feeling kind of embarrassed about the questions I had failed, since I was now reminded of how basic they actually were.  I was chatting with a coworker about it and mentioned the interview, and told him that I could see why they didn&#x27;t want to hire me.<p>He&#x27;s my buddy, so he tends to say nice things, but he said (paraphrasing from memory): &quot;but wait, doesn&#x27;t that prove the opposite?  The moment you needed to do tree traversal, you knew exactly where to go look.  You know about these algorithms, you&#x27;ve done them and taken exams on them in the past, you just don&#x27;t walk around ready to implement these algorithms on the spot.&quot;<p>So ok, BFS is so basic that I&#x27;ll probably never forget how to to it again.  But right now, this moment?  I&#x27;d have to reason back through it.  To get really sharp (especially since I won&#x27;t know the questions in advance), yeah, I&#x27;d have to hit the books for a while.<p>Just how many times do I need to re-take my Data Structures and Algorithms midterm?