The graduation from Hogwarts doesn't necessary proves that the magician is capable of performing difficult spells.

As far as I understand, most of the mages treat magic strictly on need-to-know basis. Most of the spells learnt in school become completely forgotten, just like they say that an average man uses about 300 words in everyday life, though he or she does certainly know more. All I wanted to say is that we can't judge as to whether some person is capable of doing the curse after Hogwarts or not.

One of the most important parts in successful spellcasting is the emotional condition of the caster. Remember, that magic reveals itself during childhood at the moments of the most intense emotional shakes. The students on Moody's lesson didn't possess enough emotional charge.

Graduation from Hogwarts doesn't necessarily prove that the magician is capable of performing difficult spells.

As far as I understand, most of wizards treat magic strictly on a need-to-know basis. Most of the spells learnt in school become completely forgotten, just like they say that an average man uses about 300 words in everyday life, though he or she does certainly know more. All I wanted to say is that we can't judge as to whether some person is capable of doing the curse after Hogwarts or not.

One of the most important parts in successful spell-casting is the emotional condition of the wizard. Remember, that magic reveals itself during childhood at the moments of the most intense emotional shakes. The students on Moody's lesson didn't possess enough emotional charge.