what are 83 things that causes person to forget things?

Shalom, Thank you for your question. I am unaware of a source that there are 83 things that cause forgetfulness (I might once have known such a source, but may have forgotten it …:) . If you can send me a source for such a number, I’d appreciate it. The major list of things that cause forgetfulness is found in the Talmud, tractate Hori’ot, from page 13b. Here is a copy of the Talmud, with a small commentary included. Blessings – The Sages taught in a baraita: There are five factors that cause one to forget his Torah study: One who eats from that which a mouse eats and from that which a cat eats, and one who eats the heart of an animal, and one who is accustomed to eating olives, and one who drinks water that remains from washing, and one who washes his feet with this foot atop that foot. And some say: Also one who places his garments under his head. Correspondingly, there are five factors that restore forgotten Torah study: Eating bread baked on coals and all the more so one who warms himself with the heat of the coals themselves, and one who eats a hard-boiled egg [beitza megulgelet] without salt, and one who is accustomed to eating olive oil, and one who is accustomed to drinking wine and smelling spices, and one who drinks water that remains from kneading dough. And some say: Also one who dips his finger in salt and eats it. The Gemara elaborates on the baraita: One who is accustomed to eating olive oil restores forgotten Torah study. The Gemara notes: This supports the opinion of Rabbi Yoḥanan, as Rabbi Yoḥanan said: Just as eating an olive causes one to forget seventy years’ worth of Torah study, olive oil restores seventy years’ worth of Torah study. The baraita continues: And one who is accustomed to drinking wine and smelling spices restores forgotten Torah study. The Gemara notes: This supports the opinion of Rava, as Rava said: Wine and spices rendered me wise. The baraita continues: One who dips his finger in salt and eats it restores forgotten Torah study. Reish Lakish says: And that is the case with regard to one finger. The Gemara notes: This is parallel to a dispute between tanna’im. Rabbi Yehuda says: One finger but not two. Rabbi Yosei says: Two fingers but not three. And your mnemonic for the fact that the dispute is between one and two fingers is kemitza, i.e., the ring finger. When one presses his ring finger to his palm, there remain two straight fingers on one side and one on the other. Ten factors are detrimental for Torah study: One who passes beneath the bit of the camel, and all the more so one who passes beneath a camel itself; and one who passes between two camels; and one who passes between two women; and a woman who passes between two men; and one who passes beneath a place where there is the foul odor of an animal carcass; and one who passes under a bridge beneath which water has not passed for forty days; and one who eats bread that was not sufficiently baked; and one who eats meat from zuhama listeron, a utensil consisting of a spoon and a fork, used to remove the film on the surface of soup; and one who drinks from an aqueduct that passes through a cemetery; and one who gazes at the face of the dead. And some say: Also one who reads the writing that is on the stone of a grave.