I was reminded recently that humans have a great capacity for noticing new things, yet we readily lose sight of things that haven't altered for a long time. It's part of our survival mechanism.
Very similar things happen with many of my clients too. They book in with known problem areas, but when I start the massage I pick up other muscle knots, pains or strains that the client hadn't been aware of, or that they remember being there a long time ago but hadn't noticed playing up since.
Two things are happening here. Firstly, my thorough checking of the client's muscles is picking up things that haven't yet “made the headlines” i.e. the problem isn’t serious enough to be announced to the conscious mind in the form of pain. The good news is that by spotting and treating the problem early I can prevent these unwanted headlines appearing later on, keeping the pain away.
Secondly, in situations where I find something that the client remembers having a problem with in the past, what's probably happening is that the client’s awareness of the problem has decreased, even though the problem has not gone away. I think of it in this way: if pain signals are not listened to and acted on after a period of time, the pain shuts off or becomes part of the "background noise", whilst the problem continues without recovering.
We become accustomed to the situation and put up with constant shoulder aches, stiff lower back, or problems putting on a coat. Only when someone else spots it do we realise how bad it is and how long we've been putting up with it.
My advice to you: don't put up with aches and pains, especially if you've had them for a long time. Come to see me and let a fresh pair of eyes (well, hands really!) help you deal with your problems, past, present and future.