How to justify your charname knowing spells no one else can use?

[Morgoth]

I'm referring in particular to Olvynspells: https://forums.beamdog.com/discussion/76732/v2-4-1-olvynspells-148-new-spells-for-bg-ee-bg2-ee-iwd-ee-and-eet

In reality your party seems like it can learn these spells too, but I would like to find some lore-reasons, if there are any, for either you/your party being the only ones able to use them.
 

Edited May 17 by Morgoth

[Graion Dilach]

Because RandomGraionTweaks's spell scroll distributor tweak picks up the OlvynSpell scrolls among the available picks the spellcasters can receive, that allows me to headcanon that the enemy mages are also aware of those spells, they just decided to prepare the more commonplace ones.

[Morgoth]

Thanks, I will give it a thought.