I tore mine a little bit in June last year when I tore my MCL. They were both assumed to heal naturally. However, throughout ski season any forward landing, especially when backseat, would hurt. I overshot a jump in December a little bit and that hurt it a ton. I couldn't ski for a couple weeks after that. It was basically a constant ache when skiing, then a sharp pain with any tough landing.
It had been bugging me so much I finally went back into the doctor and he said the meniscus tear never healed, and actually got worse instead..... so I am getting scope surgery to clean it up this Friday.