It has been estimated that only about 12-15% of the nerves in your body are sensory nerves. Sensory nerves let you feel things like heat/cold, pressure, and pain. Only about 1/3 of the sensory nerves deal with pain and discomfort. All other nerves deal with conveying some other function/information to body parts.
So realistically, how you feel is at best about 4-5% accurate as to tell you if you are functioning at your God given potential.
Chiropractic is about allowing your body to function as close to 100% as possible. By restoring normal alignment and function in the spine we allow a more complete brain-body connection. When that happens it usually means that you feel good, but more importantly it allows your body to function better. Remember that just because you do not feel pain/discomfort or do not feel bad does not mean that there is no nerve interference due to subluxations that are causing your body to malfunction.
That is why regular weekly check-ups to the chiropractor are important regardless of how you feel. If you are subluxated, you will be adjusted. If you are not, you won't. But you won't know unless you are checked.