I read stories about adults trying to find their biological parents all the time and think why do they want to do such a thing? What are they hoping to gain --

I read stories about adults trying to find their biological parents all the time and think why do they want to do such a thing? What are they hoping to gain -- by becoming close with their biological parents who possibly have knowingly abandoned them, they also risk alienating and hurting their adoptive parents. Sounds pretty selfish to me.