Usually people do not know a lot or nothing at all about their former incarnations

The human being living on earth knows nothing of his former incarnations with the usual external consciousness. Indeed, we know that there are people among the theosophists who after a relatively short time know a lot of their former incarnations. Once I got to know a group of people in a European city where Seneca [Seneca (~1–65 A. D.), Roman philosopher], Frederic II of Prussia [Frederic II of Prussia (1712–1786)], the German Emperor Joseph II [German Emperor Joseph II (1741–1790)], the Duke of Reichstadt [Duke of Reichstadt (1811–1831), Napoleon Franz Bonaparte von Reichstadt, son of Napoleon I.], Madame Pompadour [Madame Pompadour (Jeanne-Antoinette Poisson) (1721–1764)], Marie-Antoinette [Marie-Antoinette, Queen of France (1755–1793)] and still some other people were sitting together at a coffee table. But apart from those who know so much about their former incarnation, after they have learnt a little theosophy, people do not know a lot, as everybody knows, or nothing at all about their former incarnations with their everyday external knowledge. Since, as true as it is that the human being knows nothing of his previous incarnations by that which just the present human cycle gives him, it is true that he has everything for his will development after death that remained to him from previous lives. There it is different between death and a new birth. Whereas people know nothing about their previous incarnations between birth and death here, they have all the forces of their previous incarnations in themselves in the life between death and a new birth, but also that which has always been experienced between death and a new birth.

Source: Rudolf Steiner – GA 159 – The Mystery of Death – Cologne, 19th June 1915