I have a bum knee. I had arthroscopic surgery on it about 20 years ago. They made 3 tiny incisions in my knee and repaired the torn cartilage. Know what my diagnosis was? Bartender's Knee. Don't laugh. It's a bitch. Three other girls at this particular bar had already had this same surgery. After a good while of working on your feet, it makes your legs, ankles, and knees weak. Add the constant squatting to get liquor bottles, and it takes it's toll on your body. Your "well" drinks are right in front of you, but you go through so many bottles a night that you're squatting to get them all the time. It can be quite a good workout if you work at a very busy bar where you're running the whole night making and delivering drinks; trying to get to everyone in time. More drinks = more money. This knee gets painful when there's a lot of moisture in the air. Like today.