I found my grandchildren were buying far too much food, not freezing it, and throwing it away on the very date suggested as 'best by'. When I took over the housekeeping, I used my common sense (and my nose), froze food as soon as I got back from the supermarket and didn't tell them what the date had been. Nobody suffered any ills.
I often go away for a couple of weeks and leave things in the fridge and eat them when I get back. I have eaten yoghurts which were two months old without any ill effects, and I have travelled to many tropical countries with less than British standards of food safety. I am never ill.
I grew up at a time when there were no fridges in working class houses and no money spare for throwing food away.
I have also noticed the advice about keeping pickles, etc. in the fridge. For goodness sake, isn't that why they are pickled in the first place, so they will keep? However, I have noticed that jam does go mouldy.
Babies and children need their surroundings to be kept reasonably clean, not as hygienic as an operating theatre (hm, possibly not a good comparison with hospital infections being as rife as they are). My family say I have a stomach 'like a leather bucket' and I put this down entirely to my mother's relaxed attitude to hygiene. I don't get colds either. (That could be, of course,because I live alone and rarely have contact with other people!)