More than once, I've run into someone who has replied, "They made fun of Jeremiah, too," when he was ridiculed for saying something ridiculous.
Yes, and Alan Greenspan and I both chew our food before swallowing, but don't ask me to run a national economy.
Jeremiah is hardly the only figure in the Church whose mantle people like to assume on utterly trivial grounds. Are you obnoxious? You must be as learned as St. Jerome. Do you complain about bishops? Gosh, when I close my eyes I can't tell whether you or St. Catherine of Siena is speaking.
Jeremiah wasn't a prophet because he was ridiculed. He was ridiculed because he was a prophet. (And incidentally, the ridicule he endured was somewhat more substantial than being insulted on an Internet mailing list. Don't be so quick to claim his mantle; God just might let you put it on.) And he was a prophet because God called him, a calling recorded in a fascinating passage:
The word of the LORD came to me thus: Before I formed you in the womb I knew you, before you were born I dedicated you, a prophet to the nations I appointed you. "Ah, Lord GOD!" I said, "I know not how to speak; I am too young." But the LORD answered me, Say not, "I am too young." To whomever I send you, you shall go; whatever I command you, you shall speak. Have no fear before them, because I am with you to deliver you, says the LORD. Then the LORD extended his hand and touched my mouth, saying, See, I place my words in your mouth! This day I set you over nations and over kingdoms, To root up and to tear down, to destroy and to demolish, to build and to plant.
Those first words, "Before I formed you in the womb I knew you, before you were born I dedicated you," are well known -- I suspect for their beauty and profundity more than their utility in public debate. God knew -- and, being Love, loved -- each of us before we even existed.
But then there's that word "dedicated." Douay-Rheims has "sanctified"; other translations have "set apart" and "consecrated." The idea is of something (in this case, someone) made holy by being given over entirely to God's use. When a church is dedicated, it becomes a church, a house of God, not merely a building where Mass is sometimes said. Consecrated virginity is not a decision to go public with the determination to remain a virgin; it's a giving over to God one's virginity, which thereafter is holy and set apart from the things of the world.
Are we all dedicated by God before we are born, or was Jeremiah an exception? Well, one traditional interpretation of this verse is that Jeremiah was justified, washed free of original sin, before he was born, much as St. John the Baptist is said to have been when he leapt for joy at the sound of Mary's greeting. In that sense, no, we aren't all born free of original sin; most people aren't holy and righteous in God's sight at birth.
Still, before we were formed we were known, and if our personal dedications did not happen before birth, that doesn't mean we are never to be dedicated by God. What is set apart is set apart for a purpose, and for us humans (if you'll pardon the utilitarian language for a moment), our purpose is to work out God's plan for His creation in time. God's plan would not be perfect, God would not be perfect, if there were people who had no place in His plan, no purpose in His creation.
So yes, we are, all and each of us, known from eternity to be sanctified in time. Whether the time is before or after birth is a secondary matter.
[As for that utilitarian language, I excuse it with a reference to the Baltimore Catechism's "God made me to know Him, to love Him, and to serve Him in this world, and to be happy with Him forever in the next."]