When you haven't done sport for an extended period of time, and cannot perform like you previously could. Similar to how all the pro basketball players lost their powers in the movie Space Jam.
Swimmer 1: I've been out for a month, it feels like I'm swimming through custard.
A small piece of information. Derived from the word ken, used often in the scottish language and is synonymous with knowledge.
Person 1: "Hey I don't get this shit. How do you solve this problem?"
Person 2: "I got that one. Give me some kenlets on this assignment and I'll help you w/ that one."