It's the simple things, like hearing his youngest daughter Madeleine say "hi," which give Scarborough father-of-three Simon Lewis the biggest buzz.
Two years ago, Mr Lewis and his wife Laura were told Madeleine had autism - a diagnosis which helped explain the sleepless nights and alarming unresponsiveness.
It has been an arduous, expensive journey, but after hundreds of hours of professional therapy, the four-year-old is making significant progress.
"When Madeleine was diagnosed it was very scary - I've never been so scared in my life," Mr Lewis said. "You conjure up images of your child not being able to talk or interact.
"I think the heartbreaking thing for parents is when you're around neurotypical children and they say, 'Hello mummy, hello daddy,' and your child doesn't do that."
Madeleine's therapy draws on the principles of Applied Behavioural Analysis, which Mr Lewis says is more widely used and subsidised in other Western countries.
The Federal Government offers $12,000 grants for early intervention autism treatment at a maximum of $6000 a year until the age of seven.
Mr Lewis said the ABA therapy - which the Government recognises as the only established intervention treatment - costs about $1300 a week. He was introduced to ABA by the founder of Perth's now-defunct LEARN Foundation for Autism, Mandy Mason.
Ms Mason will run the Rottnest Marathon tomorrow to raise money for Madeleine's treatment and awareness for ABA.