I would imagine some mountaineering or polar expeditions it might be very difficult to judge the optimal between too much gear and food and clothing, and too little, as the more extreme the expedition, the narrower the difference between the two. Also, the less fit you are, the narrower the difference. In theory, when too much gear is also too little, we need to stay home.

For most of us on most of our trips, the margin is very wide, so it is more a matter of finding a personal preference still within the bounds of safety. Even in such circumstances there are risks, as we often put ourselves in harms way by pushing one extreme, or some extreme, or another, either in the clothing, or gear, or perhaps the distance we travel or the decisions we make along the way. So it might still be useful from time to time, to consider in our judgement, something half way in between what we think is too much and too little, rather than push one extreme or the other.

Such decisions are often best decided over a cup of tea.