Everyone else has got one, must have one
I remember going home to my mum saying “I must have X, because everyone else has got one.” Mum was quite clever, she used to say “they haven’t all got one, only some of them have.” She was right unfortunately and I learned how to fend off difficult questions. This works well until you are confronted by a large thug who doesn’t understand reason but c’est la vie! I now realise how difficult it must be for parents whose kids are just the same except now it is not just a ten bob toy, but a £2,000 computer. Luckily I don’t have children.