Are you a mushroom, too hahaha

The general idea is that a mentally ill old lady squats under a tree with a black umbrella every day and never talks to others. Then the doctor squatted beside her with a black umbrella every day, in order to understand what she was thinking. After squatting for a month, the old lady finally talked to the doctor. The old lady said:

Excuse me … are you a mushroom, too?