Oh, no, I understand what you're saying, and I know exactly what you mean.
I think all the time when I'm alone. On the computer, no, but in bed, yes, very often. I can switch it off when I'm distracted, of course, but when I'm not it's all over the place. I think of stupid things I did way back when and my thoughts aren't "OOOOH WHY DID I DO THAAAAAAAT" or "THAT'S SO CRINGY" but "haha I was 16 years old" or "whoops oh well that happened", never calling myself an idiot or anything like that.
Maybe it's due to my total acceptance that the person that I was yesterday isn't me, just someone extremely similar, and that that similarity becomes far muddier the farther time goes back, that as a creature I am fluid and constantly evolving in personality and reactions, with only the most basic of instincts remaining the same over time. Yeah, I've made noises, sang and hummed to myself all the time for the last 18 years, but my taste in what I sing has changed all the time... things like that. I never, ever feel bad about what I've done years beforehand, and what I've done recently can still be rectified.
And yes, not thinking is good. I realize that I can't remember thinking after 20 minutes of not doing so in a way that I would remember (of course I'm always thinking; I'm just not always paying attention) and I just think "oh well".
I think I may be happy to an unhealthy degree.
I always come back to the fact that I am no less shitty than that person was.
Just before sleeping, heh, how familiar. In general, I follow Putnam's way of thinking more or less, although it's more 'God I WAS such an idiot back then, gotta remember to never do that again. Ever.', though I'm occasionally kicking myself for majorly screwing a certain thing up in the past, but then it's 'Eh. At least I had the opportunity to gain experience on how not to screw it up again.'
Then I go back to doing what in retrospect will have been being an idiot. Yay!
Basically, King Henry complaining that peasants have it easy because they don't have to think about everything, so they can fall asleep. It's a bit of Ye Olde Royal-Worlde Problems, but I get the sentiment. Life would simpler (albeit far less interesting) without an active mind.
I find being left without anything to think about or focus on doing - I'd call it boredom but it's not the kind of boredom you get when listening to someone droning about something that doesn't interest you, it's simply the mind-numbing absence of stimuli - almost physically painful. Over a certain threshold, I start acting irrationally and doing something,
anything, to just stop having to endure that feeling.