Why don’t the digestive enzymes in pancreatic juice make fun of the pancreas’ own tissue?

Because the pancreas has a physiological barrier membrane to prevent spontaneous digestion: under normal circumstances, most of the enzymes secreted by the pancreas are inactive zymogens. The zymogens are isolated from the cytoplasm. In the pancreatic duct of the pancreatic acinus Contains trypsin inhibitory substances that can inactivate a small amount of biologically active or prematurely activated enzymes. So the pancreas does not digest itself.