Is 16 "Old" In Teenage Years.....asking for a friend

I guess it wouldn't have mattered as much if it wasn't for the fact that they've been experiencing life the same way since they were 12. No relationship changes, big milestones, parties or teenage experiences, physical or emotional growth, really. And now they're basically an adult (society's most neglected). They can drink, drive and get a job, but haven't really done or experienced anything.