I do not think there is any thrill that can
go through the human heart like that felt by the inventor
as he sees some creation of the brain unfolding to success . . .
Such emotions make a man forget food, sleep, friends, love, everything.

Nikola Tesla
Habit is necessary; 
it is the habit of having habits,
of turning a trail into a rut,
that must be incessantly fought against 
if one is to remain alive.

Edith Wharton