TikTok has crowned its newest obsession, and this one might actually be worth the hype. What sets the Lock-In apart from older internet fads is its flexibility. One TikTok user even shared that her Lock-In was simply learning to say no more often to protect her peace. “This type of trend resonates deeply with a very human desire for structure, responsibility and outwardly visible progress,” she said. The Lock-In just puts language to it and creates a shared rhythm for making the last stretch of the year count.