From an early age Jar Jar stood apart from his peers. He was extremely clumsy and underestimated. Gungans naturally assumed that he was an idiot. Since they had no advanced medical technology to confirm this they relegated him to menial tasks. Eventually his clumsiness began to get him into trouble. This led him to be grouped with the criminal element in the Gungan cities and eventually his expulsion despite the fact he had never intentionally or maliciously done harm to anyone.
After several years of living on his own in an environment not suited to his species and with no outside help, Jar Jar was unwittingly swept up into a galactic conflict beyond the scope of any Gungan's involvement in history. Saved by Jedi MasterQui-Gon Jinn from a pair of battle droids Jar Jar was taken with the Jedi and his padawan to rescue the Queen of Naboo and escape the planet. Eventually they made their way to Tatooine and Coruscant before heading back to the planet Naboo in an attempt to liberate it from invaders. Jar Jar was welcomed back into the Gungan fold and made a General in the Gungan army. Despite his ineptitude, he was responsible for the destruction of many battle droids and even took out a tank by himself. After the battle he was rewarded for his efforts and his links to Naboo human government lead to a position as the Gungan liaison in the senate. Also, it meant he wouldn’t be around to break all their stuff.
After multiple attacks on the Naboo Senator's life required her to go into hiding, Jar Jar volunteered to take her place in the senate and to vote in her stead. He was told to trust the guidance offered by the Chancellor and Senator Bail Organa. When they both agreed that an army was needed, Jar Jar again volunteered to do the necessary duty and assume the risk involved in introducing the Military Creation Act. Throughout the Clone Wars, Jar Jar was sent on dangerous missions with Jedi and the Naboo senator or on their behalf. His continued success was often viewed as a surprise because of his clumsiness and assumed stupidity. At conclusion of the Clone Wars and after the deaths of his close friends, Anakin and Padme, Jar Jar retired from his position of liaison and left the planet of Naboo.
For five years after the end of the clone wars Jar Jar traveled from planet to planet originally with the intention of fulfilling Anakin Skywalker's dream of seeing every planet in the galaxy. On the Planet Croatia he met several other Gungans who had set up a small settlement and met a doctor that specialized in Gungan physiology. After being examined it was discover that Jar Jar had a birth defect that messed up his equilibrium and explained his clumsiness. He was cured with a simple non-invasive procedure. After years of having to deal with his handicap, Jar Jar now found himself to be stronger faster and smarter than other Gungans and most other beings. He sought out Bail Organa and began to work for him as head of security for his family on Alderaan. Once Bail became involved in the Rebellion, Jar Jar immediately volunteered for a dangerous mission to find a military project that was receiving large amounts of supplies and personnel. He was able to use a false identity and infiltrate the system because no one related the confident and stable Gungan with the Gungan that worked so closely with the Senator from Naboo. He eventually made it to the Death Star and was able transmit information about the station to rebel spies. He was captured and locked up in the holding cells on the Death Star. Darth Vader himself attempted to find out who he was and where he sent the plans but Jar Jar never reveled either and Vader never recognized the Gungan. He was still a prisoner when Luke Skywalker blew up the Death Star.