Years of orphancy which was offscreen.
She survived in Jakku in a tough society. She knew how to fight. And Kylo had a blaster wound.
Luke took off an arm of Wampa without any proper experience with any weapon. And he force pulled a saber without any kind of training.
Rey was beaten by Kylo fair and square after her training which shows that her training was not enough to overcome Kylo.
Luke beat his father after his training, one of the most powerful force user in history.
Rey did not have any chance to meet her family. Luke at least redeemed his father.
Well, is she owerpowered? Sure. But many heroes and heroines are.
That doesn't mean I don't have any issue with Rey. Using mind trick was out of nowhere. Let alone lack of training, she shouldn't have heard anything about it in the first place.
By the way, where is my Ahsoka? Isn't it orange friday today?
The problem is that people dont understand how the Force works and why most of the prequel jedi (Republic Soldiers) were weaker than any empire Jedi(Ahsoka, Obi-Wan, Ezra, Kanan, Luke, Rey).
The main difference between Luke and Rey is that Rey is extremely open minded (she wanted at all costs to escape her reality and belong to something), but Luke (he just wanted to leave Tatooine and have adventures) on the other hand he was closed minded (during ANH and ESB).
When the Force talks to Rey, she immediately accepts blindly while Luke has second thoughts, this is showed comparing Padawan Luke(X-wing levitation) and Padawan Rey(Rocks levitation), remember what Yoda said about weight\size been insignificant to the power of the Force.
In comparison with dealing with the Force Rey is like Obi Wan and Luke is like Anakin. The force works like a faith power up, if the user is trully connected to the force he is unstoppable (Oby x Anakin).
Anyone can use a lightsaber, but only a force user can actually wield properly the weapon.
Talking about Ahsoka, she become way stronger when she left the Order exactly because of what i explained above, when she was a padawan she was just a soldier of the republic, she was better than most but bellow the better knights like Anakin.
But when she is expeled and cames back in season 7 she finds her way in the force and is able to defeat Maul and later desactivate a Inquisitor's lighsaber using just will, in season 7 she became a true Jedi Knight and after her duel with Vader she hits the level of Master.