If the mumps is caused by the mumps virus, you only get it once in your life because after you get mumps once, your immune system is immune for life and you don’t usually get it a second time. However, if the cause of the mumps is another virus, it is still possible to get it a second or even a third time. This is because there are many other viruses that cause mumps, such as influenza, parainfluenza, or other viruses. In addition to these viral infections, mumps can also be recurrent if there is something blocking the opening of the parotid ducts and this factor is recurrent. So the main thing to determine if you can only get mumps once in a lifetime is which type it is. The virus that causes mumps is not only the mumps virus, but also many other viruses and non-infectious factors.