People thinking they have a good solution when they don't is an interesting problem. A good technical example of this is parsing xml with regex or generating xm

People thinking they have a good solution when they don't is an interesting problem. A good technical example of this is parsing xml with regex or generating xml with string.format, I've had to explain to colleagues why this is bad so many times and many of them are stubborn and wonder why we should change something that "works". Initially they think the difference only carries academic significance, such as claiming i++ is faster than ++i. Usually you have to show them an example of valid xml that fails the regex before they realize that it is a problem. Kornish wrote a comment above about how important it is to know that certain problems have known solutions, in the same way its equally important to know what is not good "solutions" to certain problems.