Terminally-ill Australian Shaun Wilson-Miller, 17, has become an internet sensation after accidentally posting a heartbreaking and inspirational farewell message to the world on YouTube.

Shaun, who has been told by doctors he does not have long left to live after his body rejected a second heart transplant, was only trying to post his tragic goodbye speech to his friends on Facebook but due to a mistake put it on YouTube and woke up to find it had more than 10,000 views. As I post this it has 1.3 million.

The Video, in which he shows no signs of self pity – encourages watchers to seize the day and make the most of their lives.

Live life to the fullest because you never know what’s going to happen.