…I suspect the vast majority of Overcoming Bias readers could not achieve the “happiness of stupidity” if they tried. That way is closed to you. You can never achieve that degree of ignorance, you cannot forget what you know, you cannot unsee what you see.
The happiness of stupidity is closed to you. You will never have it short of actual brain damage, and maybe not even then. You should wonder, I think, whether the happiness of stupidity is optimal – if it is the most happiness that a human can aspire to – but it matters not. That way is closed to you, if it was ever open.
All that is left to you now, is to aspire to such happiness as a rationalist can achieve. I think it may prove greater, in the end. There are bounded paths and open-ended paths; plateaus on which to laze, and mountains to climb; and if climbing takes more effort, still the mountain rises higher in the end.
Climbing the mountains of the mind is aided immensely by solitude. It need not take the form of physical isolation; indeed, physical isolation often is impossible. But, with practice and determination, mental solitude is attainable, even in the midst of tumult.