Well the thing about getting any material to learn from is that it closes the learning curve and also makes the experience richer once you get experience.
It all depends on how good you are applying knowledge from a classroom into the real world, in other words how good at you are at being educated.
There are people who will go through many seminars never using anything in the real world, never observing situations where it would be useful in the real world, and then say the seminar was crap. Well for any learning experience to take place, you have to apply the stuff.
If you go through all of David DeAngelo's seminars you will learn so much information that once you are out there in the field you will recognize pretty much exact situations he's discussed. You will be able to read other people's state of mind as it happens, and you will know why they are thinking what they are thinking.
If you observe a situation hundreds of times in the field, you may eventually learn some narrow aspect of how it works and use it to your advantage. But if you learn about that kind of situation from someone who knows their crap like David DeAngelo or whatever, you will see many more dimensions to it and use ALL Of them to your advantage.
Its really all about expanding horizons and learning to think outside the box.
the course of life and experience...sorry though, you can't buy it on dvd.
That's not entirley true. For example, if you are taught that certain things result in certain actions, like giving a woman flowers on a first date leads to total AFCdom, then you can learn to avoid those behaviors without having to go through that yourself.
Basically these seminars and stuff will teach you some proven things that have been tested, so you don't have to spend years of time learning and figuring out them for yourself. That way whatever experience you have will build on that, and make you even better.