To have ambition is to have the drive to grow and get better. Growth is the natural state of the human condition, the opposite of which is stagnation, decay and eventually death. But how is that different from being ambitious?
For an ambitious person, ambition forms an integral part of their identity. This ambition is apparent in the words they use, the relationships they cultivate and in how they spend their leisure. Rather than ambition serving them, it turns into their master.
To be ambitious is to pursue one’s ambition at all cost. And that is precisely when it turns costly.