Why can't Jiangxi people understand Jiangxi dialect?

Gan dialect is the most widely used language family in Jiangxi. However, due to the unique geographical environment in Jiangxi and the repeated immigration of northern immigrants, there are great differences in Gan dialect. For example, Nanchang dialect, as a kind of Gan dialect, is obviously different from Gan dialect in other areas, so that it is difficult for even Jiangxi locals to understand each other's dialects. Jiangxi has a long history and profound cultural heritage. It is the cradle of China's revolution. From Anyuan Workers' Movement to Autumn Harvest Uprising, from August 1st Nanchang Uprising to Jinggangshan Struggle, from the establishment of Ruijin Central Revolutionary Base to the Long March of the Red Army, from the three-year guerrilla war in southern Jiangxi to Maojialing in Shangrao concentration camp, a series of major revolutionary activities took place in Jiangxi. Therefore, Jiangxi is known as the "cradle of red" and is rich in red cultural resources.