Fatigue is not only about physical movement
Travel fatigue often surprises people because it appears even when the itinerary does not look extreme.
That is because travel draws on more than energy in the narrow sense. It also draws on attention, uncertainty tolerance, and administrative capacity.
Why solo travel intensifies it
Traveling alone means every small decision stays with you. You monitor timing, directions, spending, safety, documents, and communication without offloading those tasks to a companion.
A better mental model
Think of travel fatigue as the accumulation of small demands that each seem manageable but together reduce clarity and flexibility.
That model usually explains the feeling better than simply saying you need more sleep.