It's not random. Those who are adopted choose it before they are incarnated on earth. Everyone chooses their parents, their birth circumstances, their early years and even major events in their lives.
That is your incarnated personality speaking. "You" (as your earth personality) may not want it, but YOU (as the higher self/soul) choose your current incarnation before you were born for a reason. Usually, people are incarnated here to learn things, to grow spiritually and to fight to create a better world, they aren't incarnated to have a trip in Disneyland and have a basically meaningless life full of enjoyment and hedonism. That would be spiritual stagnation. Your higher self understands that, but often human, earthly personalities can't get it, that's why they feel very unhappy when chasing meaningless pleasures.