Whether or not you *must* buy an umbrella depends entirely on your personal circumstances and preferences. Here's a breakdown of factors to consider:

• Your local climate: If you live in an area with frequent rain, an umbrella is a practical necessity.
• Your tolerance for rain: Some people don't mind getting a little wet, while others prefer to stay dry.
• Your commuting habits: If you walk or take public transportation, you're more exposed to the elements than if you drive.
• Availability of alternatives: Do you have a raincoat, waterproof hat, or other means of staying dry?
• Upcoming weather forecast: Check the weather forecast for the next few days. If rain is predicted, an umbrella might be a good investment.

Ultimately, the decision is yours. Consider the above factors and decide if an umbrella would make your life more comfortable and convenient.