You know that feeling? When you’re in the design sweet spot? Creating something new. Doesn’t matter what it is, could be mundane. But you have tunes in the background. Every curve you create seems to work. Its all clickin’?
I’m in it. Its like bad sex 
i know what you mean. the rare times that happens it’s usually on some shitty material like napkins and bank statements.
i think your referring to ‘flow’
Flow is the mental state of operation in which the person is fully immersed in what he or she is doing, characterized by a feeling of energized focus, full involvement, and success in the process of the activity. Proposed by psychologist Mihaly Csikszentmihalyi, the concept has been widely referenced across a variety of fields.