It was a great experience. You learn a lot. You manage stressful situations, whether that's a disagreement about a travel route or food -- food stress becomes real. To your point, my age group was probably 16-23 and things did become a little cliquey at first. But at some point or another everyone will have to rely on someone else and your age doesn't matter at all. Someone in my group had previously done an Outward Bound expedition and compared the NOLS experience to be much more adult-friendly.