I was first taught land nav by the government. I thought it was hard then. Looking back, I see now that the instructors knew about what we knew as students--nothing.
I got into orienteering races about 9 years ago. I learned more in 15 minutes with one of those guys than everything I had learned in my life up until that point.
Orienteering is a great way to learn and get in shape. For those of you who don't know what it is, it's a course with waypoints all over the area. Maybe 10-15 for a given course. There is one master map with the points plotted on it. You have a blank map and you have to transfer their plots to yours before the race.
Once the race starts, you have to be the first one to go find all of the points and pass the finish line. The actual point is a small orange flag with a punch on it. Sometimes they get really hidden and they are just like 8" across so you may have to be right on top of it. You'll learn to count paces, hit handrails, bushwhack, read terrain and everything else. Plus you basically have to do it running if you want to come in near the front. So, there isn't a whole lot of time to sit and think about what you want to do.
I like the ones that are done at night in the winter. You have a headlamp, a map, a compass. You have to be right on top of it at night. You could spend the entire race looking for one flag if you aren't careful. Talk about a workout.