Getting stuck in is to fully commit oneself (mentally, physically, emotionally, and spiritually) to a cause of great meaning; be utterly committed and determined to reaching your objective. If a person is fully stuck in, nothing can stop them from reaching success. It is a very respectful term that can be voiced to those you love in order for them to have good luck/fortune.
Trying hard to fit in with your kids, but failing miserably. Derived from Rocket League when parents play the game with their kids, but can't get their car off the ceiling as heard on What's That Word Podcast.
Teen 1: My mom got her 'mom' jeans out thinking she could fit in with us.
Teen 2: That is some serious stuck-on-the-ceiling parenting.
To be stuck in a predicament. To be caught up in a tight situation. To my knowledge from back in the day, the term originally came from Chuck Norris films because he was always getting caught up with bad guys.