The Walking Dead doesn't usually provide much insight into the characters' lives before the outbreak changed everything, because this show is about dealing with the present and not dwelling in the past. But in "The Big Scary U," the show revealed some details about Negan's life before he led the Saviors, specifically about his first marriage. But what happened to Negan's first wife on The Walking Dead?
Negan got into the details of days gone by while he was trapped in the RV with Father Gabriel. They were surrounded by a zombie horde with few means of escape, so Gabriel decided to press Negan for a confession. He admitted his own past failings (when he'd allowed his congregation to die during the earliest days of the virus) in an attempt to convince Negan to do the same. Negan played it off initially, but then he revealed what he considered his biggest weakness: his wife was dying during the outbreak and he failed to mercy kill her when the moment came. Cool story, bro.
Negan didn't offer up his wife's name or many details of their marriage, outside of the fact that she was sick and he was cheating on her. The confession added some shading to Negan's history, but it also made it clear that he'd been a jerk from day one.
The death of Negan's wife obviously had a profound effect on him, particularly because his failure to end her life after she turned was something that still lingered with him. But it was hard to have any sympathy for Negan losing his wife after you found out that he was unfaithful to her. He considered her his "only real wife," disregarding the entire group of women he coerced into sleeping with him in the Sanctuary, but he didn't treat her any better while she was alive. He just idealized her after she died. Her death wasn't even about her at the end of the day; it was all about the impact it had on Negan.
The backstory presented in "The Big Scary U" appeared to be taken mostly from the comics, which delved into Negan's pre-outbreak life in the issue called "Here's Negan." It had a little bit more to say about who Negan was previously: he was a gym teacher and ping pong coach, something that was potentially alluded to on the show when he mentioned that he used to help kids who were going down the wrong path. He had been having an affair, but his wife's terminal cancer caused him to end it; the show and the comics shared basically the same conclusion when it comes to her death. Negan was unable to kill his wife once she became a zombie, so he got a young boy at the hospital to do it for him.
But the comics did something the show did not: revealed her name. Negan's wife was named Lucille, so his weapon of choice was named in her honor. After lying to his wife and cheating on her, Negan chose to hold onto her memory by giving a barbed wire-wrapped baseball bat her name. There's nothing more meaningful than having a murder weapon named after you, right?
The episode may not have shared that detail, but it did imply it in a scene between Negan and Gabriel before the confession. Gabriel was asking if Negan had been married before he manipulated a bunch of women into being his "wives," and Negan muttered to himself, "Lucille, give me strength." While it was depicted as him just talking to the bat before wielding it, those in the know could spot the reference to the bat's namesake.
Now viewers know a little bit more about what made Negan into the man he is today: even more of monster than he was yesterday.