Yeah... the intention is that the number of spells you can memorise matches the number you may cast, but you're right in that the text may not be clear on that, other than stating that cast spells are erased from memory and that you may memorise the same spell multiple times.
Theoretically, known, memorised, and cast spells would be like having three layers: a wizard may know a lot of spells, but he can commit only a certain number of those into memory (but still be able to use scrolls and cast from spellbooks), a subset of which he might be able to actually use (casting a spell being more taxing on mind and body than memorisation itself). But AS&SH doesn't work this day - until you make a house rule ;)
Last edited by Ynas Midgard (1/16/2016 10:13 am)