There are psychological costs to making decisions. Since choosing can be difficult and requires effort like any other activity, long sessions of decision making can lead to poor choices. Similar to other activities that consume resources required for executive functions, decision fatigue is reflected in self-regulation, such as a diminished ability to exercise self-control (Vohs et al., 2008). (See also choice overload and ego depletion.)
Vohs, K. D., Baumeister, R. F., Schmeichel, B. J., Twenge, J. M., Nelson, N. M., & Tice, D. M. (2008). Making choices impairs subsequent self‐control: A limited‐resource account of decision making, self‐regulation, and active initiative. Journal of Personality and Social Psychology, 94, 883‐898.