I lost my daughter in Pwhelli market one year, she was missing for 20 minutes. We walked around with a policeman and no sign. then he said, so you have a plan if she gets lost and we said yes, "go back to the car, but it is half a mile away". He told my husband to go and look and there she was sitting on the bonnet, very angry that we hadn't come to look for her sooner.
A few years later she took her brother to look for some horses at Teg's Nose near Macclesfield one Bank Holiday and I didn't find them for over an hour!
It really shakes you up, I don't know how people whose children go missing for years or worse carry on. A few minutes is enough!!