Let me take the first question. Differences between men and women? Psychologically there are differences, physically there are tons of differences. If you don't know much about men and women yet, it is really proper that you ask your father or mother. You can talk about this with us in the interviews if you have a specific problem there, otherwise I'll leave that part.
As to Theravadin Buddhism, why only men can become a Buddha, that is what is written. Don't get hung up about the question, don't get hung up about only a man can become a Buddha or not, it has no relative importance to our lives. The books say only a man can become a Buddha, fine. In our history, according to our history of 3000 years back we have a man whose name was Siddhartha Gautama who became a Buddha. Other Buddhas, I don't know, but we have only one in this whole history of our existence, and it was a man. The books say it always has to be a man, okay, who is going to argue with a book? If you want to argue and discuss it with a book, good luck. So I can't tell you why, it is just simply the way it is this time around.
Now, to the first part of that question, why Theravadin Buddhism discriminates against women? As to the way Theravadin Buddhism began, you have to put your mind into a whole different frame, you have to actually imagine India 600 BC. You have to imagine a society that was totally controlled by men, except in the house, because women did have power in the house, but the general society was totally controlled by the men. The religion of that time was called Brahmanism, not Hinduism, it was called Brahmanism, totally controlled by men. Women were slightly better than cattle maybe, I don't know. Brahmanism wasn't quite as bad as some other religions that have been on the planet. There was human sacrifice, animal sacrifice as well. There was a very rigid society where men were simply in-charge, that is how it was. That is not how it is today. It is a different society. So when you think about how Theravadin Buddhism began, you have to bring yourself back to that time.
Now, what the Buddha did was so revolutionary that it scared all the Brahmin priests like nothing else. It freaked them out. They didn't like him. Some of them conspired to try to kill him, because one of the things he said was that women could become enlightened. Nobody had said that before. He said it. Women did get enlightened according to the scriptures, a lot of women got enlightened. He allowed women to start the order of nuns. Totally bizarre, totally against society, absolutely a wrong thing to do as far as the Brahmins were concerned, but he did it. But he only could go so far. To make total equality for women, he couldn't do that. The basic reason of why he did not make it totally equal for women was because if he did, the Brahmins would have destroyed him and then Buddhism never would have survived at all. So he had to adjust to that time period, he could do so much as an improvement but no, he couldn't turn the world upside down.
He did turn the world upside down with the fact that he did teach women the exact same teachings as he did men. He said, "Women, you can do it, men, you can do it, too." I don't remember which story it was exactly but there was a layperson that didn't like being taught the Dhamma by a nun and they complained to the Buddha. And the Buddha asked, "What exactly did she say?" And they repeated it. The Buddha said "I would have used these exact same words." What higher praise can you give to another human being, the Buddha saying he would have used the exact same words that person did? And it happened that that person was a woman.
So as far as the Buddha was concerned, this whole issue of discrimination against women, it didn't happen. If we look at it from our societies' conditioning today we would say, "Oh, the women were discriminated against." One of the rules the nuns had was that they were always to travel in pairs, they couldn't walk alone. Do you know what this was for? Because women are the weaker sex and there were plenty of men raping women at that time. One of the nuns who was a non-returner, third level of enlightenment, almost got raped because she was alone. So the Buddha made a rule to protect the women, because physically they were not strong enough to defend against men who really wanted them. So some of those conditions that the Buddha put on the women, from today's point of view, we may think, "Oh, there is discrimination there". But quite frankly in many places around the world, in our western societies, in Thailand, quite frankly, there are many places where it is better if women aren't alone. So, something to keep in mind, the Buddha really did not discriminate against women.