Most of my characters learn in a standard manner, but I have one that learns by telepathcially entering people's mind and just extracting the information instead of lessons and practice.
What's a standard manner?
You have to know and define it to keep your character believable.
By painful experiences generally.
The hard way?
'standard way' - Lessons, hard choices, mistakes things most do daily.
The character I was referencing there, although fully developed, her story wasn't then. Her lessons, training and that sort of information she optimizes her learning process through the telepathy but obviously, like everyone/everything around us, she's quite fallible .