I used to think computer science never mattered because I rarely used algorithms and never saw the value of algorithm-based interviews (I still don't ;) ). The few folks I asked also concurred so I felt I was right.
the mathematical concept of sets in number theory. The set of integers can be seen as a type - only values such as 1, 2, 3 are integers; decimals (e.g. 1.1) or irrational numbers (e.g. π) aren't members of the integer set.