Siblings fight?

My parents run a restaurant back home and recently my Mom was asked by a very disturbed customer, a father, about his own kids. He said his kids are always fighting, about who gets to drive the better car down to who buys a better phone. Like us, they are 3 siblings. He said if one of them coincidentally got better stuff than the other, they would fight. Literally fight due to the unfairness. Mom was surprised they are at their 20s. This father was worried when he died, the siblings would break out in fight of his inheritance. I have a strong feeling they might, they just might.
Mom asked me if I ever got this jealousy feeling with my sister and brother. It got me recalled back to our childhood.
Our family had not much money to spare back then. Well, I am the luckiest as being the youngest, I was born into a family that was getting better. I didnt remember the difficult life for the most parts.
I remembered though how Mom bought things for us but she never did buy for all of us at once. Most of the times only one of us get new thing at one time. I get passed down handphones, clothes, watches from my sister. Nope, I honestly never thought it's unfair. Mom taught us never to be envious of others. She would patiently talked to us, reminding us of the life values that we should fight for and not these artificial values. 
Till today, we siblings give the best to each other. They are the closest people in my life. Why wouldnt they have the best from me? Who would have the heart to see their siblings fell downer anf felt happy? That's just utterly sick and selfish.
I remembered still a few years ago, me being me, asked Dad for an iPhone. I had just started work back then. I told Dad, you see everybody at work has it. Everybody got a new iphone and I dont. Dad shot me a look and he said simply in Hokkien, "No money then dont try to show off". Brought me back to earth that word did.