I'm still not sure, if the old solution was better than the new memory system. You needed more investment (skill points) to even learn higher level skills, now you need hardly any. Also now you need to use attribute points to use more skills instead of using skill points to do it, which would be still more logical?

Or you could just go for a D&D approach, number of skills usable are depending on your level (like mages in D&D and their spells).