A teacher gives learning. But in the process he gets something in return. He gets learning in return.
When you teach, you get greater insights into your subject. You dissect the topic in depth.
When you teach, you learn patience - the way to explain with calmness, and composure.
When you teach, you learn how to communicate. The right tone, style, content, and volume to effectively deliver your message.
When you teach, you learn to give. To give your knowledge, to give a part of yourself.
To teach is to learn !