It's when to come to a place like this, you realise how fortunate your own life is.
The Duchess of Cambridge has been meeting families of children being treated at Evelina Children's Hospital.
Like Jack Sneddon, who was born in November in Glasgow with half a heart.
At four months old, this little chap has had open heart surgery twice.
His mum has been here since the day he was born, and stays at the Ronald McDonald House - which Kate was visiting today.
It allows parents to stay close to the Evelina London hospital where their children are being treated.
She also had a posy presented to her by Isabelle Randall whose younger brother Luke is being treated for severe epilepsy.
Some of the parents stay here for months on end - free of charge.
One couple the Duchess met come from Gibraltar.
Mia - who is 8 months old - has had her kidneys removed.
She needs dialysis every night for 12 hours while she waits to get older.
Her father - Dion Mifsud - plans to donate one of his kidneys when his daughter is 2 years old.
They've been in London since she was born in July.