I heard off some learned people that Allah's pens have already written the destiny of every soul that has come that is present and that is to come long before the creation of mankind.
This was in explanation to the Hadith of the Prophet Mohammad PBUH, regarding pre-destiny, about who will go to hell and who will go to heaven, since Allah swt already knows what choices we will make in life, then He already knows who is destined for Hell and who is destined for Paradise.

Anyone else have any knowledge on this to share.

Allah swt knows best.