You can't rely on others when you are in trouble. It's a metaphor or motto that it's better to open an umbrella yourself than to let others open an umbrella for you. It means to try your best to solve the problem without relying on the help of others when facing difficulties or challenges. Instead of relying on others, it is better to prepare yourself and master the methods and skills to solve problems, so as to better cope with challenges and difficulties. This sentence also reflects the spirit and attitude of self-reliance and self-reliance.