Nothing like this man had ever been seen on Privet Drive. He was tall, thin, and very old, judging by the silver of his hair and beard, which were both long enough to tuck into his belt. He was wearing long robes, a purple cloak that swept the ground, and high-heeled, buckled boots. His blue eyes were light, bright, and sparkling behind half-moon spectacles and his nose was very long and crooked, as though it had been broken at least twice. This man's name was Albus Dumbledore.
Source: Harry Potter and the Sorcerer's Stone (Book 1)
"Tell me one last thing," said Harry. "Is this real? Or has this been happening inside my head?" "Of course it is happening inside your head, Harry, but why on earth should that mean that it is not real?"
Source: Harry Potter and the Deathly Hallows (Albus Dumbledore)