How about... I do not remember a lot about him?.. wouldn't that be acceptable?
him, not he, in English, but él in Spanish, not lo or le. Could someone explain the difference grammatically?
Lo and le are object pronouns, just like any other object pronoun, they are unstressed, you cannot finish a sentence with an unstressed word in Spanish, hence the rule "don't finish a sentence with a preposition", since 99% of prepositions are unstressed. There are prepositional pronouns in Spanish, and as the name suggests, they are used after prepositions, most of them are the same as the subject pronouns except for mí, tí and sí (reflexive), the rest (él, ella, nosotros, etc.) remain the same