I'm curious what change requests, from testers, clients, or managers, programmers have encountered that seemed really simple but were in fact really complicated.
One thing I've hit was being asked to change a word in the title of a window. However, the title of the window was in fact localized in a library and was shared with several applications. Changing it's title in either title would mean either changing where it grabbed the data (ugly and inconsistent with the rest of the code), changing the dll (will impact other software), or adding a hard-coded fix (hacky).
"I'd like to use Oracle instead of SQLServer for the database."
"can you make it bigger?" in reference to the sizing of radio buttons.. back before CSS
Back in my college days I worked on a side project for a client. It was a medium sized Win32 desktop application to do some 2D diagramming and every step of the way and every demo was great. The client liked it. Finally, I was ready to deliver it and be done when they asked if I could just make it run on the web first.
Classic "missing-requirement-kills-project" scenario.