Here's a common myth based on old science: the number brain cells you have at birth are all you'll ever have. In fact, our brains produce new neurons every day in the hippocampus and we can make good use of them with strong learning habits.
We have two types of memory: working memory and long-term memory. Most people can only handle four or five pieces of information in their working memory and at some point in the learning process must transfer those things to long-term memory. This won't happen in one day; it takes time and effective studying, and getting good at it is the main purpose of these articles. Exercise is a very effective way to make sure those new neurons survive and help you learn and remember better. It also provides your brain with the right environment to naturally and effectively transfer new information to your longterm memory.
Metaphors and analogies are one of the best ways to help you remember important concepts. For example, the ideas of electrical potential and current are analogous to pumping water up a hill and letting it run back down - the battery acts like a pump, the water is the current, and a resistor is the downhill part of the course. The more visual your analogy, the easier it will be to remember later, and much later.
When studying write things down, especially formulas. Make an effort to write neatly and deliberately. There is a strong connection between writing and memory - much stronger than between reading (or typing) and memory, in other words writing stuff down helps build strong neural connections.