I got some tools to work on during speech therapy but im kind of confused

I got some tools to work on during speech therapy but im kind of confused I recently started speech therapy and its been hard to accept getting help. Makes me feel very weak and strange. The one thing im struggling to understand is that i was told to talk to myself in front of the mirror couple of times a day but heres the thing when i try to speak alone in front of the mirror my speech is very fluent I havent stuttered once. Why is this so and should i continue it?