Why are people always trying to find someone?

why do some people need companionship more than others?

So for example, my sister is always dating someone, has a new boyfriend or sleeping with different men. I on the other hand have never had a boyfriend, never been on a date and never slept with anyone. I am 22 shes 24.

I have no desire to find someone, I am more focused on getting a career and focusing on my music and art. Shes just focused on... I don't know, it seems like finding someone to support her.

But I find this in a lot of other girls my age, they are always looking at boys, going on dates or fooling around with someone different which there is nothing wrong with and I know that if anything I am the minority but I just wonder why... it is human nature?

is it actually a goal in most peoples life?!