A lot of people I know chuck out food once it's gone past it's sell by date without even looking at it.
I remember, years ago, travelling across American by Grey Hound bus with a friend who made me chuck away cheese between hostels as it had been out of the fridge for too many hours!
I'm not at all like that and refuse to chuck anything away until it's been smelt and tasted.
I ate this yogurt last night and it tasted perfectly normal. But being two and a half weeks "off" I wonder how many people would have just chucked it away without even opening it? I think a lot of it comes with this live style we have chosen, when your preserving and storing a lot of your own food you have to start using your own judgement again rather than just trusting what's written on a packet.
What's the longest time past a sell-by-date that anyone has eaten something and which foods do you avoid risking it with?