Yes, it's really specialization vs freedom vs flexibility. Clerics are in-between, they must prepare their spells each day, but from the whole (smaller) list of cleric spells. So
- Wizards must choose the known spells at each level from a big global list, they cannot change later, and they must prepare a small selection of known spells each day. They can learn additional spells from scrolls.
- Sorcerers must choose the known spells at each level from the same big global list, this number of known spells is smaller than for the wizard but they don't need to prepare them, they can use any of them. They cannot learn from scrolls.
- Clerics must prepare their spells each day directly from a global list, so they know more spells than wizards and sorcerers, but this global list is smaller than the wizard's / sorcerer's big global list. They don't need to learn from scrolls.
(that's a simplified comparison)
Tough choice
Now that I've tasted it, I think I prefer the cleric's way, even if I miss some of the exotic spells that wizards enjoy. With a wizard or a sorcerer, I always have a hard time selecting spells, and I'm invariably frustrated to know so few of them.