I changed my username (my first puzzle +train) [lvl 1+] (Ended)

I recently had an important exam, which I successfully passed, so I thought I could celebrate that with my first train. I also changed my steamgifts username (it was csireke before). I simply wanted to use Warden, but that's already taken (oh well).
So my (supposedly easy) puzzle would be this short riddle:
Why did I choose warden as my username? There is some sort of "logic" behind it. If you found out, use the same logic to this: cK4lYn, then delete the last one.

The puzzle leads to a simple 1+ giveaway, and from this giveaway you can jump on the train which I used sgtools for. (The rules are stricter there.) Since this is my first attempt at a puzzle and also a train, I made the giveaways two weeks long, so that I would have time to change something if there's a problem. Also it gives me time for additional hints if the puzzle would turn out to be too hard. (Please let me know if you think it is.)

Hint #0 (just in case)
You don't need to know anything about me (personally) to solve this, every information you need should be accessible to you.
Hint #1 (if you got stuck)
For the people who are thinking to themselves "Just how long have I been trying to solve this...", take a little break and try again later! :)