Millennials, brace yourselves. YouTube's first video just turned the big 2-0.It was on April 23, 2005, that YouTube co-founder Jawed Karim uploaded a grainy 19-second video "Me at the zoo" to his brand new digital platform. Twenty years on, the video showing Karim in front of an elephant exhibit at the San Diego Zoo has more than 355 million views. Karim, along with co-founders Chad Hurley and Steve Chen, sold the platform to Google for $1.65 billion the following year.Since the mid-2000s, YouTube has become a pop culture juggernaut. The platform reports more than 20 trillion videos have been uploaded over the last two decades.