My definition of wisdom is:
If person is opened for every potential event, circumstances, and opinions. It is also consciousness, that You can be totally wrong, that even most reliable theory can be wrong/ even most stupid theory can be right. Just think about every possibilities. Of course, not like: "Oh, what the wind blows, that is what I will think". Be ready for everything, as much, as it possible.
It is also experience, knowledge, and Your ability to analyse them, and drawing conclusions from them.
Because of studing, You just know what Kant or Platon was thinking about. How they were looking at the world. You have more knowledge, maybe You can create more theories with this knowledge, because they showed You new perspective. But even if You will have mind of all world philosophers, You will be still not as wise, as someone who is aware that he can be wrong, he can be right, something can change, or turned out completely into absurdal thing/form/way.
The truly wise person, can understand another person, mostly. Even if they don't agree in situation, wise person should understand motives/circumstances/thinking way, of this second person.