When you get a project ready for launch and the client finds a huge error that has to be fixed first, except it's not a huge error, it's something they requested two months ago and forgot about.

Did they document it in the written requirements?

That should be another rant, the written requirements for this project basically said "product configurator" and has been defining what that means throughout the project. It was fun for the first two months, now we're in the eighth :(

im in the same boat. boss didnt ask for detailed product specs. fluctuating between the impostore syndrome and blaming the pm xD

To make it worse, the original AM on this project stopped paying attention to it half way through due to his other client demands. I had to step in and play AM and Dev for a few months until another AM could step in.