Power?
"Humans act as if they had power as a terminal value" probably matches reality better than "Humans act as if they had happiness as a terminal value".
My original suggestion was "knowledge", but that may make you equally value knowing Pokemon trivia - I value useful knowledge, not any old knowledge, which seems to be another way of saying I value (a form of) power.
Though also, I don't see much of a reason to care about "terminal values" except when talking about maths and economics and decision theories and the like - any talk of "terminal values" is highly uncertain and likely to be wrong, so it's not something I'd take to heart.
That feels too much like lost purposes. "Power" refers to something that can be used to fulfill values in general.
It's the sort of thing you'd acquire if you haven't figured out what you really want.
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