It is not 'breaking character' for a GM to provide a memory prompt to a Character in the game. Doing so is treating the Character as a Character who recalls In Game stuff that the Character had learned. This is applicable to a lot of game systems. Systems I have seen this applied to, from long ago to last week:
1. D&D
2. Traveller (original)
3. Mothership
4. Blades in the Dark
5. Dungeon World/Fellowship
6. Runequest
And that's just off the top of my head.