Scar tissue has the potential for massive change, no matter how old. The above photos are scars from a dog bite that happened about 5 years ago. The photos show the before and after of an hour long scar work session.
Apart from being a cosmetic problem, scars can also tug on muscles and connective tissue and create motor control problems, often resulting in pain and other injuries. Having scars worked on, no matter how old or small they are, can have an incredible effect on the body. If you've had an injury that resulted in scarring or a surgery that you never felt like your body properly recovered from, you should have your scars evaluated.