I'm rather annoyed by the duelling requirement in the nature-based spells aspiration. One of my Sims did the knowledge-potions aspiration and finished it quite quickly. Aga's been stuck on the duelling goal for ages, and now that Helly's doing the spells aspiration, she's stuck, too. They have to win three duels against three different spellcasters to get past it, and it's rather difficult to arrange them with strangers. (It doesn't help that they've both had the 'awkward embrace' curse, so they keep dropping interactions because someone wants to hug them.)
I might cheat past this one.