I've only done this once, though one time I did forget my PIN (my very first debit card, only had it 3 days). The time I forgot my PIN, the very friendly and attractive girl behind the counter had no problem with me leaving my wallet with them whilst I drove home to pick up the cash I conveniently had lying around in my room - why said cash wasn't in my wallet, I have no idea. The time I forgot my card, I wandered into the station, made a very quick and quiet phone call in the corner, and pretended to be very interested in anything that was on sale - oil, magazines, crisps - until my mum arrived with my card to save the day. Luckily I only live a mile from my closest petrol station, however I no longer use that place because I always ended up being served by the same friendly, attractive person and the embarrassment was too much.