While not denying this, it seems to me that there are some knowledge gaps about Indurain's early career:
Age 19: National Champion in the Road Race for U23
Becomes Pro at 20
Age 20: Wins ITT in Tour de l'Avenir
Age 20: 2nd in Vuelta prologue. Youngest ever yellow jersey wearer (4 days), a record he still holds
Age 22: Finishes his first TdF
Age 22: Wins 2 ITTs and GC in Tour de l'Avenir
Age 22: Wins Vuelta a los Valles Mineros, a hilly 5-days stage race in Asturias
Age 24: Wins Volta a Catalunya, 7-days stage race
Age 24: Wins Paris-Nice
Age 25: Wins mountain stage in TdF (Cauterets)
Age 25: Wins ITT in Criterium International
Age 25: Wins Paris-Nice
Age 25: 3rd in Flèche Wallonne
Age 25: 7th in Vuelta a España
Age 26: 2nd in TdF ITT. Wins mountain stage in Luz Ardiden. Finishes 10th at 12' 47" of Lemond. It is estimated that he lost about 12 minutes working for his team leader Delgado
http://translate.google.com/transla...o/1228124670.html&sl=es&tl=en&history_state0=
Age 26: Wins Clasica de San Sebastian
Age 26: 2nd in Vuelta a España, lost time to winner Mauri in 2 TTTs and 2 ITTs, queen stage suspended due to snow.
The rest after this is well known. I'm not sure we can say that he came out of nowhere. He did not progress uniformly is his GT standings, but we cannot say that of his TT ability or his results in 1-week stage races including hard climbs. He did never ride well under cold/rainy weather (Vuelta was in April at that time and the weather in the mountains is awful at that season of the year), and for the Tour he had a clear boss (Delgado) until 1990.