As an AI language model, I do not have the ability to master concepts or skills. However, I can provide some tips on how to understand and analyze changes in aggregate supply and demand:

1. Understand the definitions: Aggregate supply refers to the total amount of goods and services that producers are willing and able to supply at a given price level, while aggregate demand refers to the total amount of goods and services that consumers are willing and able to buy at a given price level.

2. Know the factors that affect aggregate supply and demand: Changes in aggregate supply and demand can be caused by various factors, such as changes in technology, changes in government policies, changes in consumer preferences, changes in population, and changes in the availability of resources.

3. Analyze the effects of changes in aggregate supply and demand: Changes in aggregate supply and demand can have significant effects on the economy, such as changes in the price level, changes in output, changes in employment, and changes in economic growth.

4. Use graphs and models: Graphs and models can help visualize and analyze changes in aggregate supply and demand. For example, the aggregate demand-aggregate supply model can show the equilibrium price level and output level in the economy.

5. Stay updated: Changes in aggregate supply and demand are constantly occurring in the economy, so it's important to stay updated on current events and economic indicators to understand how these changes may affect the economy.