I think it can be quite mystifying though. It is difficult to see outside your own sphere of experience.
Family help must make a phenomenal amount of difference. Having help towards things (or things bought outright) such as a house deposit, car, driving lessons, wedding, even uni living costs/tuition fees (rather than student loans) would have freed up loads of money to put towards savings for example, family help with childcare makes a huge difference to someone's net income, these things are not small and yet if you assume everyone has them/forget that other people have them (because you don't) then it can be hard to imagine the difference in lifestyle.
When you constantly have to pay out for basic living expenses and just the normal life emergencies (funerals, urgent travel, car accident, loss of work through injury, appliance dying on you) then you don't have a chance to build up savings for more emergencies let alone save for nice things.
And people usually socialise with others around their same income level, which can give a distorted impression that "the average person" is earning roughly the same as you, and of the scale of "normal incomes". That's why for one person £30-40k will seem like a really high income and for another it will seem impossibly small, and for a third person it might seem quite average/normal. If you think of 30-40k as high, then you probably won't even consider somebody on 100k+ to be a "normal person" at all, you imagine they must be impossibly rich with a highly luxurious lifestyle.