All his life Andrew Davies has had a sense of not fitting in, that he was somehow broken, weird or there was something wrong with him.
That was until he discovered he was autistic at the age of 70.
"It's just who I am and how my brain is wired... how I experience the world is just different," he said.
Research has suggested that like Andrew, there are many others who have spent a lifetime not knowing they are on the autistic spectrum.
Between 250,000 and 600,000 people over the age of 50 in England may be autistic but undiagnosed, a study of primary care records in England has suggested.
That would mean more than 90% of autistic people over 50 were undiagnosed, its researchers have said.
"Autism was seen for many years as a childhood condition but it's a lifelong condition and as people get older they remain autistic," said Andrew.