This means that there are steps or stages throughout one's life in which the mind and personality undergo changes. For example, one may take a step as a child going from rarely having their own thoughts and feeling to creating their own opinion. This would be a step that the person is taking. Hope this helps!
The best answer for this question would be to talk to the cashier, in situations like these the customer is always right and knows exactly what they want, and if that doesn't work out ask the manager so he can get the correct coffee he wishes for.
