A common experience in TikTok is for a new audio to appear (many people can use the same audio in their videos), the algorithm detects that you like it (you let it play to the end), so the app feeds you other videos with that same audio. After you see a few you think, wow, this audio is everywhere today!
Then you tap on the audio to see that there are only a few dozen videos with it. It feels like it's a huge viral movement, but it's not.
It takes less repetition than you'd think.