Assumptions are often a barrier that block creativity.

It was 1969. One day, Jerry Weintraub calls Colonel Tom Parker, Elvis Presley’s manager, to persuade him to take Elvis on his first nationwide tour.

Parker says, “No.”

But Jerry was an aggressive talent promoter and concert manager. So he keeps calling Parker every day at 8:30 in the morning. Every single day. For a year.

And every morning Parker gave him …