“There is also an obstacle that is from the nature of the mind itself.
We get moods — sometimes we are all right, we can go on,
but sometimes we feel heavy, we feel dull, we don’t feel like proceeding.
This mental heaviness could be due to food, it could be due to cold weather,
it could be just the nature of the mind.”
– TKV Desikachar Religiousness in Yoga
‘Antarāyāḥ, Obstacles to progress, Techniques to Overcome them’
Chapter Fifteen Page 208