Jeremiah was certainly around before he arrived in his mother's womb: "Then the word of the LORD came unto me, saying, Before I formed thee in the belly I knew thee; and before thou camest forth out of the womb I sanctified thee, and I ordained thee a prophet unto the nations.-Jeremiah 1:4
We may not remember a former life. What does Ecclesiastes say about this-
The thing that hath been, it is that which shall be; and that which is done is that which shall be done: and there is no new thing under the sun.
Is there any thing whereof it may be said, See, this is new? it hath been already of old time, which was before us.
There is no remembrance of former things; neither shall there be any remembrance of things that are to come with those that shall come after.