Completely agree, this kata was pretty fun to solve!

A really fun kata which gives you great satisfaction and sense of accomplishment on solving. Analysing the test cases and making changes to the code and getting closer to the solution step by step was fun.

Also, this kata tested a variety of concepts through its numerous mini-questions (all the different terms and conditions). Great design.

Practice and analysis are the two keywords to writing such solutions. Carefully analyse the solutions that you see after you solve a problem and try to understand the logic behind it. Compare your solution with theirs to understand the difference and the clever tactics used. I can assure you that even you will start thinking out of new and innovative ways of finishing the code in a few lines in a few days.