Well, you can do some guiding of the conversation in the right direction.
For example, when the interviewer says, “Tell me about yourself, mathman.” It sounds like you typically launch into discussion of your ECs.
Instead, you should take a 1-3 second pause, and choose carefully what you want to lead with. A simple answer like… "I love swimming ", "I want to be an astronaut " or “My favorite hobby is fishing”. It will guide the discussion into some area that you want to highlight about yourself.