>>13727653your mom has 20,000 red balls labeled 1-20,000, and each one also has a random word on it.
your dad has 20,000 blue balls (heh) that are numbered 1-20,000, and also has different random words on each one. They don't necessarily have the same words, and most likely have totally different words than your moms balls.
you get ~10k random balls from your mom (+/- some amount) and ~10k random balls from your dad, but only one of each number from 1-20,000 (so your number 1 might be from mom, number 2 from dad, number 3 from dad....all the way to 20,000).
You have roughly half the genes from your mom, half from your dad.
Now, your broski goes through the same process. He gets 10k random balls from your mom, 10k random balls from your dad.
They will be a totally different mix than yours, even though you both got half and half. If you compared all the words on the 20k balls between you and your bro, there is roughly 0% chance they match, the statistics are too far out there, and in fact will be fairly different.
The 20,000 balls are your human genes, one number for each gene, and the words represent different genotypes.
