Why is meditation pleasurable? It strikes me that it is very fortunate that meditation can be pleasurable. If there was no fairly immediate rewards then surely hardly anyone would make any kind of progress towards enlightenment. It almost like it is designed to have little pleasant staging posts where the practitioner can rest before continuing onward with the journey.

But why is meditation pleasurable? Could it be insightful but barren or is there something inherent in the practice that is pleasant and the pleasant quality of meditation is a necessary quality? What do the texts say about the pleasant qualities of meditation? Is there any accounts about why it is pleasant perhaps mythic accounts or explanations?
When I took the course Buddhism and Modern Psychology, the lecture delved into the neurobiology behind meditation. Material was presented that breaks up the conscious mind into 8 centers competing to be at the forefront of awareness. When meditating, the Default Mode Network(DMN) in the mind shows less activity in fMRI scans in studies led by Judson Brewer who himself used meditation as a coping mechanism during medical school.

The DMN is the center of the mind thought to be responsible for daydreaming. The exact mechanism between meditation and pleasure in the mind is not known, but I speculate that a sort of rhythm develops between these competing centers and other parts of the brain that leads to decreased levels of cortisol and increase in pleasure neurotransmitters such as dopamine.

A point to note: Suzuki Roshi mentions in Zen Mind, Beginner's Mind, that the purpose of meditation is not too feel good or become a better person rather the purpose of meditation is to meditate.

https://en.wikipedia.org/wiki/Default_mode_network

https://www.coursera.org/course/psychbuddhism

http://www.yalescientific.org/2012/05/the-healing-art-of-meditation/