Just snuggling down after a(nother) hard day, when a thought just worms its way in - your heart starts to beat twice as fast and you end up taking AGES to drop off.
'Oh bugger I forgot to brush their teeth! Alder Hey here they come'
'What if my son never stops hitting / biting / screaming'
'What did I last do for my husband? This year?'
I could go on.
What are your guilt insomnias?