The 59-year-old star not only lost his son Jett at the age of 16, but has also been hurt by the recent death of good friend James Gandolfini - but the actor is keen to always remain optimistic.
He told the Daily Express newspaper: "I deal with it and move on. There's no point becoming angry or sad or using up important time in life.
"I know people can become bitter or cynical, I am not like that ... I cannot think about the bad things in life.
"I d not lose a moment's sleep over them because I know the truth. The downs of in life have not been significant to me."
The 'Pulp Fiction' actor revealed he chooses to focus on the "up things in life", and is grateful for how "wonderfully" he is treated.
He added: "I think of the up things in life. Moves? I love them. Music? Yes, always key to enjoyment. Dancing? I still dance with my daughter and son.
"I get to travel to place like this and be treated wonderfully. I was made so welcome with people who show genuine warmth."
Johnand his wife Kelly Preston, 50, - who have daughter, Ella Bleu, 13, and two-year-old son Benjamin- mourned the loss of their eldest son Jett in 2009 when he succumbed to a deadly seizure.