My previous neighbours liked to show off about their 'wealth' on social media. To the extent that at Christmas they would post 'Santa's been' with photos of presents for the kids. One year I popped round and noticed that the pile of presents was nowhere near what was suggested in the photo. They had posted a different photo for each child's pile, but it was actually all the presents, they had just rearranged it for each photo to look like more.
They believed that they were entitled to a flashy lifestyle and did nothing to earn it. She was a stay at home mum and he was a salesman on minimum wage, he worked for commission, but this was never cash, it would be things like an i-pad, festival tickets or a day at a spa, he also had a company car. Everything they bought was on credit, they would order designer stuff from catalogues, photograph it and then send it back. If a friend had a new designer item, this would be photographed as if it were their own. They would go abroad for three days but post the photos over two weeks. All of this was to put onto social media to pretend that they had the 'ideal' lifestyle. When in fact they were seriously in debt, had bailiffs knocking on the door and got evicted due to not paying the rent.
Aside from inheritance, credit cards and family help, I think it can sometimes come across that you have spent more on things than you actually have. Between me and my husband we have six brothers, all of which are in a trade. When we had an extension built it only cost a fraction of what others would have to pay, it was all cash in hand, cost price or freebies on the materials and no charge for hourly rate.
Another example is a colleague of mine is very into beauty treatments etc. She has five close friends who all decided they couldn't afford what they wanted so they decided to do it themselves, each went on a course and they get together once a month and do each others treatments eg one does nails, one does waxing etc. It hardly costs anything, but looks like it does.
I am not saying this is the case with everyone, but there are a lot of people faking it, don't take anything at face value, it's certainly not worth being jealous of.