A: It's quite simple, really. Just stand on one leg and pretend the other three don't exist.
For advanced users, we recommend consulting our Stand on One Leg Tips subpage for further optimization.
A: It's for the balance, man. The balance.
A: Of course you can! Just don't get too close to any open manholes. We're not responsible for your ankles.
A: Yes, there's the One-Leggers Anonymous forum. Join us, and let the balance be with you.