What did the professor mainly discuss? Why does the professor say the colonists developed their own paper currency?

Listen to part of a lecture on events leading up to the American Revolution.
    Professor:
    Okay, while I think of it, on Tuesday, I was originally going to show you a documentary film about a town in New England that was founded in the colonial period… uh, but it looks like we had a mix-up at the library, and they lent it out to someone, so I won’t be able to show it to you until Thursday’s class. So, instead of what I told you before, do the reading over the weekend and be prepared to discuss them on next Tuesday. Hope that doesn’t inconvenience you.
    Okay, now we’re going to talk about the American Revolution— what we often call the Revolutionary War—and we’ll talk about two or three laws—The Sugar Act, The Currency Act, and The Stamp Act. They were all enacted soon after the French and Indian War ended in 1763. The British had won the war and, as a consequence, gained a lot of territory. But there was a downside to their victory: the war had cost a lot of money. So, British Parliament looked for ways to make sure that trade money from the American colonies came back to Britain. The increased money would help pay for the war. The way the British decided to get that money was to put taxes on certain purchases and to put limits on what kinds of goods the colonists could buy and sell, and that’s where the trouble started.
    The Sugar Act was passed in 1764. It was actually a revised version of an old tax on sugar by-products like molasses, and it had two big effects. One, Parliament lowered the tax on molasses but increased the tax on sugar and certain kinds of cloth, coffee, some wines, and fruits from the tropics. Second, it made sure the taxes were collected—the old tax on molasses hadn’t been enforced very well. Now, what this did was, mostly, it made it more difficult for rich people—they were the ones buying the wines and tropical fruits and refined sugar, as you might imagine—to get things they wanted.
    Now, that same year, Parliament passed The Currency Act. The colonists had to buy most of their goods from home, England; that took up most of their British currency. So, what happened, of course, was that when they wanted to trade with each other within the colonies, they didn’t have any money left to use. That gave them an incentive to come up with their own paper currency. Its value was based on people’s property. You know, it was useless for buying things from England, but it was very useful for fanners with a little farmland who wanted to pay off their debts quickly. They could use the paper notes and then try to earn back the real value in produce from their farms. What did The Currency Act do? It invalidated all these colonial forms of paper currency. The colonists were told they couldn’t use them anymore. So now you have the rich merchants, the traders, angered by The Sugar Act, and you have the farmers in debt who need to rely on paper money, and they’re angered by The Currency Act.
    Alright, so now the third law: The Stamp Act. The Sugar Act put a tax on sugar, so you might think The Stamp Act put a tax on stamps, but that wasn’t the idea The idea was that there would now be a tax on all sorts of official documents the colonists used to get for free: marriage licenses, newspapers, even playing cards. Well, these were the kinds of things people needed for everyday life, so everyone—merchants and farmers alike—was outraged.
    Now, I’m leaving out some things in the sequence of events—such as that the British government adjusted some of the provisions of these laws when the colonists complained. But the main point I’m trying to make is, these laws were meant to get more money, more revenue, for the British government to pay for the French and Indian War, but the effect they had on the colonists was to make them feel as if they were being pushed around by a bunch of people in Parliament on the other side of the ocean. Up until this point, the taxes in the colonies had been administered by local governments in the colonies themselves. For the first time, Britain not only imposed taxes on the colonists but showed that it would use force to collect them. And this was the origin of the famous slogan "No Taxation Without Representation”, and it stoked the movement among the colonists to be free of British rule.