I'm guessing that the point of 'mana transmutation' is to use more power than would be possible using normal 'game' element skills, kinda similar to the spider isekai.
The way I get around this is by saying something out loud where I need to think a little before saying it, therefore remembering it easier. Plus points if it's unique to the day so you don't confuse today with yesterday. For instance, when locking the door I say "today is the 16th and the door...
This was a nice comfy series, and I feel it ended at just the right time to not get too repetitive.
Now that I think about it, it's not very often I read women referred to with '-kun'. There are a lot of rules when it comes to honorifics huh