I searched and could only find 20+ year old forum posts mentioning this, so here's the Return to Castle Wolfenstein "I need ammo!" reference in Sealab 2021.

To any surviving show creators: See? One guy did recognize the reference. And I even remembered it too! Totally worth it!

20 years ago today, July 14, 2005, I created "Link finds a WTF" on YTMND, later becoming better known today on the Internet after it took on a life of its own as "WTF BOOM!".

To commemorate this 20th anniversary, I've remastered my original WTF BOOM! YTMND in 4k. #ytmnd #wtfboom

Actual footage of my desktop on this day (and most days, to be fair). #doom #fireworks

20 years ago today, June 28, 2005, I created "What is Half-Life?" on YTMND, becoming my most popular site there which spurred an interest in creating more HL stuff. whatishl.ytmnd.com

But it left one burning question: Hey @valvesoftware.com, what is Half-Life? #halflife #ytmnd