One should continuously change, because the brain
has many centers. For example, if you do mathematics, then a certain part of the brain functions
and the other parts rest. Then you read poetry: then that part that was functioning in mathematics
rests and the other part starts functioning. That’s why in universities and the schools we change
periods every 40 minutes, 45 minutes because each center of the brain has a capacity to function
for 40 minutes. Then it feels tired and needs a rest, and the best rest is to change the work so that
some other center starts working and one relaxes. So continuous change is very very good; it
enriches you.