Explanation:

Our spirits are referred to as dark because of sadness and disappointments. This can be attributed to several factors, including negative experiences, personal struggles, and external influences.

Sadness and Disappointments:
- Sadness and disappointments can make our spirits feel heavy and dark. When we experience loss, failure, or unmet expectations, it can lead to a sense of darkness within us. These emotions can weigh us down and make it difficult to see the positive aspects of life.

Negative Experiences:
- Negative experiences can leave a lasting impact on our spirits and contribute to their darkness. Traumatic events, such as the loss of a loved one or a significant personal setback, can create a sense of darkness and despair. These experiences can be difficult to overcome and may influence our overall outlook on life.

Personal Struggles:
- Personal struggles, such as mental health issues or ongoing challenges, can also contribute to the darkness of our spirits. When we are facing internal battles, it can be hard to maintain a positive mindset and find joy in everyday life. These struggles can create a sense of darkness within us that is difficult to shake off.

External Influences:
- External influences, such as the negativity of others or a toxic environment, can also impact the darkness of our spirits. If we are constantly surrounded by pessimism, criticism, or negativity, it can seep into our own mindset and contribute to a darker outlook on life.

Conclusion:
Overall, our spirits are referred to as dark because of the sadness and disappointments that we experience in life. These negative emotions, along with personal struggles and external influences, can weigh us down and create a sense of darkness within us. It is important to recognize these factors and actively work towards finding positivity and light in our lives.