When Merlin first came into existence he had the body of a twenty six year old man and he was crying. He was sending away the body of a man he'd never met and all he knew was that he felt a deep kinship to his man.
Then Merlin was on the back of a dragon, one that he knew was named Killgarah. He cradled the man, who was alive now, in his arms and willed the Dragon to go faster so that maybe the man would survive.
All of the sudden Merlin was crouched in front of the dragon who was telling him that Arthur wouldn't make it.
"I have to try, he's my friend." Merlin yelled knowing deep down that Arthur was important to him.
The Dragon agreed to help and then Merlin was crossing the land with Arthur in tow until he sat in front of a fire with Arthur and told him about his magic. The tears running down his face were not because of Arthur's reaction (he already knew that the man would accept him later) but because of he knew the man would die.
Then Arthur was fighting his enemy with no warning at all. Angry, Merlin shifted into an old man and got a wounded Arthur away from Mordred. Next he went to the top of the cliff and zapped Morgana's men with lightening.
Suddenly Merlin's magic was hot and heavy and he retreated to the crystal cave which leeched his magic away from him.
Then Merlin was back in Camelot and for the first time he felt at home despite having never been there before. Then in his bedroom Merlin was attacked by a creature which returned his magic and everything was good.
Merlin went backwards in time watching everybody he loved getting younger, fighting off magical threats, and keeping everybody safe. He watched as Uther suddenly appeared in his life and Arthur was downgraded to a prince and mourned that the longer he spent with Arthur the less the man knew him. Still, Merlin was as close to Arthur as ever and quite willing to drink out of a poisoned goblet for him.
It was after he stopped Mary Collins when Arthur tried to fight him in the courtyard that Merlin knew it was time to go. So he paced a bag and left behind the only home he'd ever had for a mother he'd met only a few times.
Years later, right after the birth of his body and right before the death of his mind Merlin lay in his cradle thinking of the past twenty-six years and moved his cradle towards his mother using magic.
Then he laughed as only a child can and thought, 'no matter how you watch my life backwards like I have or forwards, I was born with magic.'