Here, a "thought" includes processes related to perception (determining what is in the environment and where), decision-making (determining what to do) and action-planning (determining how to do it). The distinction between, and independence of, each of these processes is blurry. Further, each of these processes, and perhaps even their sub-components, could be considered "thoughts" on their own. But we have to set our start- and endpoints somewhere to have any hope of tackling the question.