Whilst I commend the quest for health and paying attention to feedback from your body, I must say I do question the "if it feels good, go for it" paradigm. Whilst this has merit in certain walks of life, and certainly has its use in finding that which makes you happy, it doesn't necessarily correlate to the most healthy thing for your body.
Think cocaine.
Now, I may be lagging on this subject a little, but it wasn't long ago I read some bits and pieces on low carbing and the adrenal/cortisol systems. If I remember right, the short of it was that chronic low carbohydrate diets (without periodic re-feeding of carbohydrate, relative to the amount of physical activity performed) can increase the release of catecholamines (think adrenaline, cortisol etc), which are involved in some of the metabolic pathways needed to create energy in a low carbohydrate environment.
From http://180degreehealth.blogspot.com/2010/06/catecholamine-honeymoon.html
These hormones, when released, cause a rise in body temperature, a rise in mitochondrial activity, an increase in mental acuity, cognition, and alertness (or at least the feeling of being sharper even if you really aren’t), a huge rise in physical energy, the release of fat tissue from fat cells, a drop in appetite, and weight loss while feeling not only good – but far better than normal.
This isn't a bad thing in and of itself, but catecholamines can create subjective feelings of energy, clarity etc. As with any hormonal system, they function entirely using feedback loops. If you flood the system with catcholamines for an extended period, they down regulate, reducing your sensitivty. This might not bode well for your long term feelings of wellbeing and could mess things up pretty bad.
So, whilst these hormones make you feel ace, if you don't have periodic resting periods (carbohydrate feeding), you may burn out in the long run. Something to consider, especially when equating subjective experience to health gain, which I think most of us paleo types fall for on this quest at least once.