As impressive as that stunt was, it highlights a much-neglected aspect of the show's narrative: Rosita's backstory. What was Rosita's life like pre-apocalypse? What was her job before the walker virus broke out? And more importantly, will we ever find out?
Unfortunately there's no information on Rosita's life before the apocalypse to be found in #TheWalkingDead comics, so it's up to the show's writers to decide if they want to reveal those details or not. But the latest episode may have given us a revealing insight into Rosita's past.
The most popular theory on Rosita's past is that she was a soldier; possibly even an engineer in the military. She did a great job at directing the group when collecting the dynamite, and definitely seemed to know her stuff.
This would also explain her mechanics knowledge, as well as her fearless, gung-ho attitude. Perhaps it's even what she and former sergeant Abraham initially bonded over. Ross Marquand (Aaron) also hinted that Rosita has military experience on an episode of Talking Dead.
Then again, she's pretty terrible at taking orders, and has the worst attitude of any character on the show. That's not exactly the makings of a great soldier.
To progress far enough in the military to get that level of explosives training, she'd have to have made it through basic training— which requires a certain level of obedience.
Her familiarity with explosives may suggest she was affiliated with extremist groups who communicated their message with violent means— terrorists. Could Rosita be hiding a dark past?