From the time Nixon was elected Senator, it was 18 years until he was elected President. (1950-1968)
From the time Reagan was elected Governor it was 13 years until he was elected President. (1967-1980)
Cruz comes up way short, when looked at in an historic light. Plenty of others have put in their training time. Governors Perry, Walker, Bush, Huckabee, Martinez, Kasich, Brewer, Sandoval, Christie, would be a list of examples.
Back during my corporate career, we discovered an interesting phenomena - why management went outside for supervisory positions, instead of promote from within.
It was because they knew all the weakness for current employees, but outsiders had no known weaknesses to them.
Cruz reminds me of that situation. In his short time he's made a few speeches, a couple of filibusters. He has no record of accomplishments whatsoever, yet he's a legend in no time.