It's a great question to ask, and the point about how strategy is future-focused is a good one. I don't particularly agree with the recommendation: everybody at the company should be strategic, and at a small company there's no room for a full-time strategist. There are plenty of great strategy books out there; Sun Tzu, Crossing the Chasm, Robert Greene's 33 strategies, 'balanced scorecard' and strategy maps ... you want to learn the general principles as well as how to apply them to the kinds of situations a startup is likely to encounter.