Hey- when you just sim past the week, it does autotrain. It may not put hours into the things you want, but it will do a form of auto-train where it puts the hours into things it thinks are important. This starts to become less useful when your stats are super high- think 99 overall- as it will put the auto-train into things that are already maxed out.
I had the same issue, where I thought I was just wasting the hours when I accidentally simmed past them, but no. It'll take care of the training hours for you if you don't allocate them yourself.