Reduces stress: Taking time off is an obvious way to recharge and reduce stress levels. But while staying home and resting is a worthy use of your time off, travelling removes you from your everyday life and lets you truly escape. Travelling lets you put aside your daily responsibilities and focus on yourself for a moment. When you return home you'll feel refreshed and have the motivation you felt drained of before you left.
Accomplishes goals: Having a travel "to-do" list and crossing things off that list keeps you motivated and positive. That list can include things like visiting certain locations or accomplishing something such as climbing a mountain or becoming conversational in the language of your next destination. Achieving those goals also increases confidence and gives a sense of success.
Makes you more flexible: Sometimes things don't go according to plan while travelling. Maybe your flight is cancelled or it rains the day you're scheduled to go on an epic outdoor adventure. It's okay -- there are other flights to take (or trains, or buses) and maybe on that rainy day you'll discover a hidden bookstore to explore or an adorable cafe to experience. Travelling helps you to be more flexible and open minded, making you more zen in your everyday life.
Teaches to be more patient: Travel can involve a lot of waiting. You'll wait in lines, for flights or at restaurants. Learning how to cope with those waits, how to make conversation with those you're waiting with and how to stay calm in frustratingly slow situations will teach you how to remain patient and calm in all situations.