God not only knew Jeremiah, He knew everyone of us before we were born, even before we were formed in the womb. Now that's a big statement for all of us.
Believe me my dear friend, God always have a special plan laid out just for you. And there's no such thing such as you being an accident. Whichever family you are in, wherever you are right now, whoever your siblings and friends are; they are part of God's plan, a purpose for your life. You just need to find that purpose and follows it.
Our differences make us special, and our similarities make us stronger. When you look at the people around you, you will see a lot of differences rather than similarities. But, remember that they are special just like how you are special in God's eye. No one in this world would ever wanted to be treated badly. Well, and if you don't want, perhaps you should start treating people better. The world works in a "I treat you how you treat me" way. Christians, be different! Be nice to people who are nice to you, be nicer to those who don't.
By then, hopefully we will realize our purpose in life. It's a tricky set of questions that always pop up for most people:
What is my purpose? Why am I here? Who am I?
Now, stop for a moment. Delete all those questions from your mind and ask yourself a brand new question:
What is God's purpose in my life?
Rethink and reshape our mindset. Mold our character. Keep our integrity. Then you will find the purpose in life.