Do you ever notice how when you're in a multi-hour stretch of positive feelings, there is this faint tug of negativity?

Whenever I'm boosted up by some new self-help book I'm reading or having just a general enthusiasm for life, I get this weird negative side effect. It seems to happen when I have long-stretches of positive experiences. For example, my friend and I had this one day that we called "Epic Sunday," where over an eight-hour stretch of time we jumped from one interesting place to the other in the city. It was a pure heroin-like spontaneity feeling like an ascending line of peak experiences. The next day, when I was alone, I felt really tired and down. Another example is when I'm in a coding fury late into the night, if someone were observing me they'd say I looked actually sickly and weak. And they'd be right: while I'd feel this internal gushing positive sensation, I also wouldn't be smiling.

In these cases, there's a negative undercurrent to the positive experiences. It's much like Newton's Third Law: For every action, there is an equal and opposite reaction. I believe that the same happens with feeling good. For any boost we get, I think there's a natural tendency within us to pull back toward a set point of happiness. (Also, when we feel down, there's a tendency to pull ourselves back up).

I've re-purposed the term "undertow" to refer to that vague negative sensation you get when you are going through high positive experiences. It helps to remind me that the goal is not only to increase positive experiences, but to also decrease negative experiences. As a result, no matter how great my day is going, the "undertow" is still something I want to avoid.

I believe that this probably has to do with the fact that almost anything your body "does" takes energy, and your energy sources need replenishing. Or maybe it has to do with neurotransmitters in our brains: any time you go through a positive experience, you're a little less receptive to positivity immediately thereafter. Maybe that's why these "epic days" crop up from time-to-time. In order to keep getting high after the initial boost, you have to seek ever more amazing things.