I just realized I spent almost all my time in middle and high school well over a decade ago "mewing" because I had a barely noticeable double chin but it fully disappeared whenever I would press my tongue hard against the top of my mouth. I have a strong jawline now and the fat is gone. I did not know it would affect my jawline. All i knew was it made my neck/chin look skinny for the duration of the effort. I accidentally helped myself in the long run by being self conscious... Weird. Wild.

Pic unrelated.