On nicknames

We have a piece of equipment called an Amplatz Super Stiff (it's a type of wire which is, as per the name, less flexible than others)...

Celery boss: "Get me a Super Stiff!"
I decide not to say, "I thought you only liked those on the weekend."
Celery boss: "Yes, that was my nickname at University!" [laughs at his own joke]
I decide not to say, "But no longer, I notice!"

I thank you.