At best, this is not productive. We mustn't forget that learning and assessing is quite valuable and has its place, but pondering in circles for hours on end is of no use in actually getting something done. The best time for this is at the end of the day, when time is limited before the "inevitable" sleep and brain-reset.
For your Colin to be reasonably productive, he must operate throughout the day in this order:
- Mornings are reserved for the brief reminder of long-term goals (but not assessment or creation thereof!) and micro-level planning of the day in pursuit of these longer goals
- Work according to micro-level plans begins and continues throughout the normal business day with periodic non-thinking breaks as necessary
- Evenings are for stopping to relax, read, ponder and socialize as necessary; it is only at this point that the assessment of long-term goals can commence as necessary