I was in Selvadorada yesterday playing with the new Hispanic content, and once again made it my aim for my sim to learn all the new recipes, but I kept forgetting what he'd learned the day before. Maybe it's just a "me" problem 'cause I'm old and forgetful. :s I know he can look in the fridge and that will tell me what he's learned, but who carries a fridge around with them? In the city, that's not always possible to look in the fridge if they're from a different neighbourhood.
Another way they could do it is as collections, like the Experimental Photo collection, but I think I'd prefer the notebook because it could then also tell us what ingredients are used for each recipe.
And!
Please please please add this for books. Right now, all my bookworms read whatever they want 'cause I don't care what they read - but if they listed what they've already read then this would give me the goal to read ALL the books! I was really surprised the other day just how many books have been added over the years. But my sims all keep just reading the same ole base game ones because there's no real incentive to buy the other ones.