Different people have different levels of magical capacity!  The Sorcerer level is where you can start using it instinctively, where magic will obey you as it comes out of you or even after it's left you, depending how strong you are.  Only one person in a hundred thousand is strong enough to be a sorcerer, though, and that one person in a hundred thousand is magically stronger than a hundred thousand non-sorcerers put together.  In principle, anyone can be a wizard!  In practice, only the top 3% of the population by magical potential should bother trying, unless they've got a tremendous obsession with doing the fine detail work on magic items or some such.  Also, to be a wizard rather than a sorcerer, you need to have the talent for understanding things that are shaped by math, and that's another big ol' filter on top of the requisite level of magical power.  The book emphasizes that nobody can blame you for lacking in magical power, but if you were born with the magical power and can't learn math, this is entirely your fault because everyone can learn math if they just try hard enough.

Kids in the system described by this textbook seem to be taken from their parents and shipped off to wizard school at age 6, if they pass a combined magic and intelligence test.

It's from some planet where successful wizard graduates automatically get awarded a harem of three pretty members of the appropriate sex.

Different people have different levels of magical capacity!  The Sorcerer level is where you can start using it instinctively, where magic will obey you as it comes out of you or even after it's left you, depending how strong you are.  Only one person in a hundred thousand is strong enough to be a sorcerer, though, and that one person in a hundred thousand is magically stronger than a hundred thousand non-sorcerers put together.  In principle, anyone can be a wizard!  In practice, only the top 3% of the population by magical potential should bother trying, unless they've got a tremendous obsession with doing the fine detail work on magic items or some such.

Also, to be a wizard rather than a sorcerer, you need to have the talent for understanding things that are shaped by math.  That's another big ol' filter on top of the requisite level of magical power.  The book emphasizes that nobody can blame you for lacking in magical power, but if you were born with the magical power and can't learn math, this is entirely your fault because everyone can learn math if they just try hard enough.

Kids in the system described by this textbook seem to be taken from their parents and shipped off to wizard school at age 6, if they pass a combined magic and intelligence test.

It's from some planet where successful wizard graduates automatically get awarded a harem of three pretty members of the appropriate sex.

Different people have different levels of magical capacity!  The Sorcerer level is where you can start using it instinctively, where magic will obey you as it comes out of you or even after it's left you, depending how strong you are.  Only one person in a hundred thousand is strong enough to be a sorcerer, though, and that one person in a hundred thousand is magically stronger than a hundred thousand non-sorcerers put together.  In principle, anyone can be a wizard!  In practice, only the top 3% of the population by magical potential should bother trying, unless they've got a tremendous obsession with doing the fine detail work on magic items or some such.

Also, to be a wizard rather than a sorcerer, you need to have the talent for understanding things that are shaped by math.  That's another big ol' filter on top of the requisite level of magical power.  The book emphasizes that nobody can blame you for lacking in magical power, but if you were born with the magical power and can't learn math, this is entirely your fault because everyone can learn math if they just try hard enough.

Kids in the system described by this textbook seem to be taken from their parents and shipped off to wizard school at age 6, if they pass a combined magic and intelligence test.

It's from some planet where successful wizard graduates automatically get awarded a harem of three pretty members of the appropriate sex.

Different people have different levels of magical capacity!  The Sorcerer level is where you can start using it instinctively, where magic will obey you as it comes out of you or even after it's left you, depending how strong you are.  Only one person in a hundred thousand is strong enough to be a sorcerer, though, and that one person in a hundred thousand is magically stronger than a hundred thousand non-sorcerers put together.  In principle, anyone can be a wizard!  In practice, only the top 3% of the population by magical potential should bother trying, unless they've got a tremendous obsession with doing the fine detail work on magic items or some such.

Also, to be a wizard (whether or not you are also a mere sorcerer), you need to have the talent for understanding things that are shaped by math.  That's another big ol' filter on top of the requisite level of magical power.  The book emphasizes that nobody can blame you for lacking in magical power, but if you were born with the magical power and can't learn math, this is entirely your fault because everyone can learn math if they just try hard enough.

Kids in the system described by this textbook seem to be taken from their parents and shipped off to wizard school at age 6, if they pass a combined magic and intelligence test.

It's from some planet where successful wizard graduates automatically get awarded a harem of three pretty members of the appropriate sex.