Thinking in general is greatly affected by two things: 1. Physical exercise. Some blend of cardio and strength training is preferable, but at least cardio is p

Thinking in general is greatly affected by two things: 1. Physical exercise. Some blend of cardio and strength training is preferable, but at least cardio is pretty much a requirement. 2. Sleep quality. Not just duration, but quality as well. If you have sleep apnea especially (many people do and don't even know it), you need to address that. Also, if you're getting _interviewed_ in such detail as a consultant, you're playing the consulting game wrong. People should just hire you based on your track record as exemplified by direct recommendations from previous customers and people within your network. One of the benefits of a consultant from a customer standpoint is that if they determine they've made a mistake, they can just terminate your contract. So an elaborate interview is a waste of time for both sides.