Unraveling Supernatural's Time Loop Mystery: The Secret to Season 15's Ending Revealed Years Ahead

In the Supernatural season 15 finale, a plot hole can be explained by referring to a specific episode in season 3. Throughout the series, Sam and Dean Winchester have always made efforts to bring each other back to life. This tradition began when John Winchester traded his soul for Dean's in the season 2 episode titled "In My Time of Dying." Dean carried on this tradition after Sam's death in the season 2 episode "All Hell Breaks Loose: Part 1." This pattern continued for the majority of the show.

However, there was a notable exception when Dean respected Sam's wishes to live a normal life with Lisa after they had managed to trap Lucifer in the cage. Dean had initially intended to save Sam, but Sam did not want to risk the possibility of Lucifer's return. Despite Sam's wishes, Castiel disregarded them and resurrected one of the brothers. Castiel also brought back Dean in the season 4 premiere episode called "Lazarus Rising." Thus, it is important to acknowledge that the brothers did not always ignore each other's desires.

Supernatural's "Groundhog Day" Can Explain Why Sam Never Brought Dean Back

When Dean died at the end of the series, Sam defied his usual behavior by choosing not to attempt his brother's resurrection. However, there is a reasoning behind this in Supernatural season 3's episode "Mystery Spot." In this episode, the Trickster, also known as Gabriel, repeatedly orchestrated Dean's demise in order to teach Sam an important lesson. The lesson was that regardless of Sam's efforts, he could not save his brother. Sam understood that this was an inevitable consequence of their line of work. If it were not on this particular hunt, it would have occurred on another, given that they had already experienced similar situations in which both Sam and Dean had died before, with Dean having faced death the most in the Supernatural series.

Furthermore, "Mystery Spot" might also explain why Sam embarked on one final mission before retiring. Continuing the family's hunting business would mean following in his brother's footsteps. While Dean would never retire, Sam constantly yearned for a life beyond grappling with supernatural creatures. He found himself repeatedly drawn back into the duty, but once he bid farewell to Dean with a hunter's funeral, he could finally pursue the life he had once envisioned.

Other Reasons Sam Didn't Revive Dean After Supernatural

Dean took on the responsibility of keeping Sam safe from a young age. In their father's absence, Dean essentially raised Sam while their father hunted monsters. However, their father informed Dean that if he couldn't save his brother, he would have to kill him. This burden always fell on Dean's shoulders, as he had to protect his younger brother. Unlike Sam, who never grew up with this weight on his shoulders, Dean always felt the duty to ensure Sam's safety.

Although Sam did make an attempt to save Dean when he was sent to purgatory in Supernatural, he ultimately chose not to actively search for him. With their family gone, Sam decided to leave behind the hunting lifestyle that caused them so much pain and loss. This likely influenced his decision to retire from hunting at the end of the series.

Another factor that may have influenced Sam's choice to honor Dean's wishes was that this was the first time either of them died without the intervention of Chuck, the higher power pulling the strings. It was unclear if Sam possessed the ability to bring Dean back since Jack was in control and did not involve himself in the lives of humans. Sam and Dean had experienced resurrection in Supernatural multiple times, but only because it aligned with Chuck's desires. While Dean would likely have attempted to bring Sam back regardless of the odds, Sam had learned his lesson from the events in Mystery Spot and opted to let Dean pass away peacefully.