Will you forget everything if you are forced to take time off from jiu-jitsu.
No, at least not according to second-degree black belt Nick “Chewy” Albin from Chewjitsu. Taking time — even months— off of jiu-jitsu will not have much of an affect on what you have learned. Anyone who has done a physical activity long enough knows that once something is drilled into your muscle memory, your body don’t simply forget it.
Chewy has the perfect analogy to describe what happens to your BJJ knowledge when you take a couple of months off. Think of a piece of BJJ knowledge like a file in a drawer. When you take time off, that file goes to the end of the drawer, but it’s still there.
Furthermore, Albin says, if you’re in jiu-jitsu for the long haul, two months is not going to be a long time. In many schools, it takes at least eight years to become a black belt. That’s at least 98 months. Even if you take two months off, that is only 1/49 of that time. That’s not exactly an eternity.
Keep training as much as you can, but if you have to take some time off, don’t worry. Not only will you still retain a lot of what’s been taught to you, but chances are, however much time you take off will probably be a small fraction of your training.