The downside to being a Cancer native is that your Moon ruler can make you pessimistic sometimes. You want to believe that the world is a kind and encouraging place. But sometimes, people disappoint you.
It's tough for Cancer to get over that. If you find yourself slipping into pessimism, try going out into the sunshine. All that natural Vitamin D is a mood-lifter.
Sharing an afternoon of fun with a close friend also solidifies your social bonds, and helps you believe in people again. When you're back to believing the best in everyone, you're much happier for it.