Happines meter should be brought back.
This time it could have some effects as well such as:
If you are happy, your learning ability increases.
If you are not, it decreases.
Maybe some other effects too as well.
It could be increased by various things, such as sitting by the fire in the evening, sleeping in a good bed, consuming some good tasting food/drink, going to sauna, walking in the forest and other such things.
Decreased when taking life of another hearthling, getting injured, eating bad food (roots, bark bread and such), doing heavy labor(alts increase playercount!) and other nasty things, like seeing a troll or sleeping in a bad bed.
Of course this can be debatable, maybe some people would gain satisfaction from the killing others, or getting injured themselves... Maybe credos could have an effect in what makes you happy and what doesnt. Doing the stuff that your credo is specialized on could make you happier.
Lot of effort to implement all these things but who cares.