I suppose this is a topic some are well versed on, some are not, and still some have no idea what it means. In basic terms, aside from Buddhism, it means that mankind’s mindset is twofold. I have often spent time trying to figure out what that really means. In reality I think I have known since I was around seventeen years old. In essence, I think it can be summed up like a split personality. When the time arises you can be someone you are not normally. Keep in mind this is my interpretation, not fact.
Having spent nearly half my life popping in and out of chat rooms, I can say I have seen this duality first hand. It is sometimes good, but unfortunately, it is mostly bad. Many people enter a chat room to escape reality. In doing this they decide that it is okay to lie, or embellish the truth. Quite frankly it really is a personal opinion as to whether this is okay or not. I have been on both sides of the coin.
On one side you have those that would tell you it is never okay to lie. Even in this medium, yet, those same people have probably been lying to themselves as well. Do any of us ever really tell the truth when we are not face to face with a person, and there are no consequences? Most likely not. Sure, we may not like about some things, but somewhere along the way we stretch the truth at the very least. Again, it is a matter of personal opinion as to whether this is okay or not.
On the other side of the argument, there are those that say it is just fine to pretend to be something you are not when you are online. After all it is just a chat room. I am not criticizing here. I have made the same argument. There are places, such as role-playing style rooms that this is exactly what you do. There are general chat rooms however that you may be trying for something else. Do so at your own risk I say. That is another story altogether.
Now you are asking, where did this Lune fit the duality of man into this? In my mind, I think the net is the perfect place to exercise that duality, if you so choose. You can be someone else, that person you long to be, and no one, for the most part, will be the wiser. Mind you, I don't condone the behavior when it adversely affects other people. I have been the victim of that myself, but it is still the perfect medium. There are some that I have met in my time chatting that have complete online persona's that are nothing like who they are in life. There is nothing wrong with this as long as it isn't at the expense of others.
Personally, I think that the duality of man means that we are all a little crazy. We would have to be to be here in the first place. Given the world we live in doesn't help either. Anyway, just some rambling thoughts of a mad hatter. Adue.