I also fall into the solo group. In the 35 years that I have been backpacking I have gone with another person less than 10 times. If someone suggests a multi person hike I usually find a reason that I am not able to go this week.

As far as getting lost it is not really a big problem where I backpack here in Michigan because there are at least two track roads all over the place. With even a large scale map it is mostly just a matter or heading in the proper direction to hit a know landmark like a major road and avoid things like large rivers etc.

I do wonder if it also an age thing. Like Pika I am strongly introverted but I think the the older generation was raised to operate more independently. The only way to communicate with friends when I was young was to get on my bike and go to see them. No smart phones or social networks. It was just too much trouble to ask another person for help or advice. Today everyone is in constant communications with others 24/7.