The brain has a limited ability to focus on multiple tasks at once, known as task switching. The context of driving, which requires constant switching, makes it difficult to multitask while driving.
The speaker suggests practicing mental acuity by putting away phones, being aware of our surroundings, and choosing what to focus on, citing subway rides in New York as an example.
The key to building self-confidence in moments of doubt, stress, and uncertainty is by taking control of what we can control, managing our physiology through breathing and visualization, and practicing it regularly to build confidence.