People can be divided into these types: strangers, acquaintances, familiar people, friends, and close friends. True friendship isn't about compliments to your face, but whether you're mentioned when they talk about friends behind your back.

Sustainability isn't a choice—it's a responsibility we owe to future generations.

Even if I fall down 100 times, I will stand up 101 times.

Innovation is the key to solving the world's most pressing problems.