This was a case where the player was having his maga casting multiple spells on the same target, as well as MuVi on those spells. It went something like this:
- Mastering the Unruly Beast (ReAn 25) to control a dog
- A variant of Maintaining the Demanding Spell with D:Moon on Mastering the Unruly Beast
- 5 different spontaneous spells to give the dog magical senses, each one sustained to D:Moon by the Maintaining the Demanding Spell variant
- Opening the Intangible Tunnel (InVi 25) on the dog, again sustained to D:Moon
- A spell to perceive through the dog's sense at a distance, again sustained to D:Moon
(And the list is incomplete...)
Except for the sustaining spells, which was a formulaic, all of these were spontaneous spells cast in a high aura (Durenmar) using Life-Linked Spontaneous Magic. The plan was to renew all of the sustaining spells every month.
And that was just one such long-term sustained magic the player was planning for.
I don't think you need amnesia to loose track of all those. Even with notes on each target, there comes a time when so many effects are stacked that you need a way to identify each one if you want to target a specific one, IMHO.