when spain first became a real power , their own fans did n't know at first .
the european champions won three trophies on the spin , but need a reboot .
likes of xavi , carles puyol , david villa and fernando torres can hand over .
juan bernat 's champions league performance signalled part of the new era .
spain still have a golden harvest to bring in from the country 's youth .
former under 21 coach julen lopetegui downed bayern munich this week .
almost all of their former youth side are playing in european competitions .