There aren't many feelings better, than when you encounter an edge case and you realize that you've already thought about this edge case in your code and it just worked.
Thanks past Óli, you did good.
Exactly! I know exactly what you mean. When you design your code and you already took into consideration some esoteric edge-case and your code is already designed to deal with that edge-case gracefully.
The feeling of accomplishment is amazing -- until another bug manifests...