After a brief stay at the École de Saint-Cyr, he studied law and was then appointed an auditor at the Conseil d’État before withdrawing completely from public life in 1846.

He also collected numerous antique objects of various natures (archaeology, numismatics, prints, silversmiths, etc.

), including a rare collection of horse bits from Galiot de Genouillac, the king's great equerry, donated by his daughter to his successor in 1546 Claude Goufffier, lord of Oiron (Deux-Sèvres) and artefacts belonging to him.

For more than 50 years, Pichon acquired one of the rarest books and manuscripts collections of his time, soon becoming president of the Société des bibliophiles français (SBF) in 1844, a society which he arbitrated efficiently, composing a number of bibliographic records intended for reissues, catalogues or publications and to the Bulletin des Bibliophiles.

He used to reside 17 quai d'Anjou [fr] in the former hôtel de Charles Gruÿn des Bordes, better known as Hôtel de Lauzun which he restored from collector's period items; moreover, he rented certain rooms to creators such as Baudelaire and Théophile Gautier and it was there that the famous meetings of the Club des Hashischins took place.