> It's true that this stuff rarely comes up and often doesn't matter for most real-world applications... but when it does, it matters a lot. The difference betw

> It's true that this stuff rarely comes up and often doesn't matter for most real-world applications... but when it does, it matters a lot. The difference between O(n2), O(n) and O(log n) is huge for big values of n. Being about to go straight to a (nearly) optimal solution, instead of hacking together something, waiting for it to burst a the seams, and then having to fix it... or being able to spot someone else doing that, can save weeks or months of development at a time. This is true, and absolutely matters. But I would suggest that developing the intuition to recognize a problem as being of a particular class, and even going further as to being able to look at the provided solution and intuit whether or not it is optimal (or optimal-enough), is a different thing than calling up that optimal algorithm from your limited brainspace. Like--if you understand the principles of what you're doing, Google isn't a much slower recall mechanism than you are, and it's less likely to have misremembered something.