Will the believer in Paradise remember the sorrowful experiences and sins he committed in his worldly life?

Matters of the Hereafter are unseen (ghayb). It has been established in the Qur’an and Sunnah that Paradise is free from anything that might tarnish its purity; there is no sorrow, anxiety, or grief in it. As for the recollection of some evil deeds in it, a weak hadith has been reported concerning this. Even if it were authentic, such recollection would not entail sadness, because the sins would have already been forgiven.