Maybe that’s not your personality which is fine, but growing up and becoming mature definitely doesn’t mean we stop having fun.
Sadly, some define growing up as the ability to do more and more “adult” things that everyone knows are harmful. Growing up does give more freedom, but it’s possibly to get older without really growing up.
Ephesians 4:13 says, “Till we all come in the unity of the faith, and of the knowledge of the Son of God, unto a perfect man, unto the measure of the stature of the fulness of Christ:”
Growing up and maturing as Christians means becoming more like Christ.
Growing up means more freedom, and that should mean more opportunities to do things that are good and helpful, not harmful.