it's not necessarily remembering specifically which ones go up and which ones only go down, it's about understanding the definitions and what they mean.
Ground under repair is part of the course proper, which has a temporary change to it. This is in the same vein as a pathway or an immovable obstruction, they are part of the course - their extents do not extend upwards, because that would be silly if they did.
A hazard is not part of the course proper so the rules are applied accordingly.
To me, it's pretty much that simple and follows the other rules related to this.
If you hit your ball in casual water and you're sure it's in there but can't see it to get it out, the ball is within part of the course so you get your free drop. Whereas, if your ball is lost in a hazard, you are penalised for that.
Look at it this way. If you hit the ball into Casual water or gur, their extents do not need to extend upwards because point of entry is not relevant. However when your ball enters a water hazard the extent of the hazard must extend upwards so that you can determine point of entry. ( and not determine point of entry from where the ball splashed ( Entered ) the hazard. As I caught one A grader doing.)