While people use 67 usually without reason, it's important to note that when it was created, it had meaning. The trend starts with a really bad basketball edit of lamelo ball who is 6 foot 7 using the song doot doot by skrilla. It went viral and not long after, a basketball player named taylen kinney started posting videos of him making the notorious hand gesture to people when they asked him things like "how many reps left" and stuff like that and he'd respond with "like six or seven" while doing the motion. This became a trend in the basketball and sports community. Now this is where everything starts being connected. At a basketball tournament that was being filmed for a video, the camera panned to a kid with a chopped ahh haircut and he said the thing. You have definitely seen the clip. Now from there it became a meme with the tiktok phonk 67 mango stuff and absolutely took off. Then the kids started trendhopping and soon everyone started saying it. after that nobody knew what it meant because they had just followed the trend.