Ohhhhhh....an 18 year old F/O. That's different...NOT. Do you really think it should be commonplace to have an 18 year old in such a position of responsibility?
Those are the years where a pilot should be gaining experience that would develop his skills and judgement.
If I was informed (as a passenger) that the 747 that I was about to strap in to and launch across the ocean was jockied by an 18 year old (in any seat) I would step off.
You don't have to agree with me. Just wave to me as you fly over with a severely reduced level of safety.