The 'That Was Legitness' meme stems from a viral 2014 Vine video featuring a young boy with a skateboard, known as the 'Legitness Kid.' In the clip, the boy enthusiastically exclaims 'Yeah, that was legitness' after a stunt, to which his friend replies, 'Yeah it was, wasn't it?' The video became a cult classic due to the boy's sincere delivery and the quirky slang term 'legitness.' Over the years, the meme has evolved into a versatile reaction tool used to acknowledge something genuinely cool, or ironically, to mock a mediocre achievement. It remains a nostalgic staple of the Vine era, perfectly capturing the spirit of mid-2010s internet humor.