It's inevitable that certain aspects of life will change over time, but we don't have to change how we tackle life. Remember to smile, try to laugh as much as possible, seek out the little joys in life, no matter how small, and always try to have fun. There are many parts of life that aren't fun or joyful, parts that challenge us. However, we can still revel in the positive experiences we have and make the most out of our time here.
Mistakes are a critical part of life. They can certainly result in negative consequences, but mistakes are important learning experiences. However, we should use those experiences to grow, learn, and improve ourselves.