Today is December 12th, 2012. 12-12-12. This is the last repetitive day this century, so let's make it a special one. Here's an idea:
In the physical therapy clinic today, you should perform three sets of twelve repetitions for every exercise. That would be quite a way to commemorate this special occasion.
But wait. Performing extra (or fewer) reps during your exercises may not be the best thing to do. Your physical therapist prescribes a certain number of repetitions for each exercise based on your current situation. Some exercises require 10 repetitions, while some require 15 or 20 repetitions. Changing ALL exercises to 12 reps may not achieve the desired goal of the exercises.
Although it may be fun to celebrate 12-12-12 by performing 12 repetitions for your exercises, you should speak with your physical therapist and perform your exercises as prescribed.