After winning the European title in 2008 and 2012 and a first World Cup in 2010, Spain did not cope with the pressure of being favourites in Brazil and were knocked out in the first round.
‘One has to differentiate between an aim and an obligation,’ Del Bosque told Marca on Monday.
‘To win the title cannot be an obligation. There is always an important lesson to be learned when you lose.’
Spain lost their first two games in Brazil, including a 5-1 drubbing by Holland, the team they beat 1-0 in the World Cup final in South Africa.
The players were accused back home of being complacent and overconfident.
‘It was not a humility issue but a sporting one,’ Del Bosque said.
‘We lost against teams that were superior to us on the pitch. We never made excuses. We never thought we were superior or unbeatable.’
Spain, who also won the European title in 1964, open their campaign next Monday against the Czech Republic in Toulouse.
‘We go into the tournament with the maximum ambition and that is to defend the title that we achieved four years ago,’ Del Bosque said.
‘It’s the same situation that we were in at Euro 2012 but with a bit more responsibility because we now have to defend two straight titles.’
Spain take on Turkey on June 17 in Nice before ending Group D against Croatia in Bordeaux four days later.