So annoying when you get 80% of the way through a project then figure out a more elegant way of solving it, but can't change it now because of time constraints

I can share my similar experience...

I applied to a job and they wanted that applicants would build a chat application to show their skills. Well I was new to web development and networking overall and made my app to work with AJAX querying database every second...and when I was submitting I stumbled upon sockets.

Needless to say, I didn't get the job :D