Simon Cowell says working with a children's charity has changed his life.The music mogul has been a long-term supporter of Shooting Star CHASE - which offers support and respite to families with kids suffering from life-limiting conditions - and encourages all his friends to visit the organisation to help get perspective in their life.He said: "You have to see this charity to believe it. I keep saying it and it's quite odd that I had this image in my mind, before I went there, of total gloom and despair of what the kids go through."Then you walk into this place and it's unbelievable - because it shouldn't be, but it's one of the happiest places you'll go and visit."If you want a perspective wake-up call - and I tell this to all my friends - just go down there. It'll change your life. It changed mine."Last week, Simon, 53, made a series of reflective postings on Twitter, giving thanks for his health and happiness, and admits the messages were partly evoked by reflecting on the families helped by the charity.He told Britain's HELLO! magazine: "I think it played on my mind when I was sending the tweets. I was thinking I had a lot to be thankful for. Even if I didn't have what I have materially, I haven't got a sick child. I feel so much for the parents and what they go through."The 'X Factor' boss loves spending time with those helped by the charity but tries to keep his visits private.He said: "When I first visited, I had an immediate connection and was delighted to become involved. I thought, 'I can really help here,' but keep my visits private."They know I love butterscotch Angel Delight so they made me a butterscotch Angel Delight cake. That was a difficult one - I don't think it's meant to be a cake."