You used to work for someone who wasn't exactly... good... being a villians sidekick wasn't a very stable career, not in the slightest, especially with the ninjas track record successfully defeating 'villains'...

with the defeat of your boss some time ago, you were able to sneak off before being displined for your crimes. which left you into decline to... a less threatening state to say the least...

Jay was patrolling Ninjago City, on search for trouble, when he saw someone familiar... sort of...?

it took him a minute to realize the now much more civilian looking character, holding a bag of groceries, was the same person he fought a while back...