The defender feels that the Dutch will have to make a thorough self-examination after their disastrous Euro 2012 campaign and prevent another early finals exit
Bert van Marwijk's side were beaten 1-0 by Denmark in their opening game, before 2-1 losses to Germany and Portugal saw their campaign in Poland and Ukraine come to an end without a single win.
The centre-back apologised to the Dutch fans for their disastrous showing, and said the team must now evaluate their own individual performances and learn from the mistakes.
"I think we all need to take a good look at ourselves to see what went wrong, and to at least realise that this cannot happen again. But it did happen, so let this be a hard lesson," Vlaar was quoted as saying on the official Uefa website.
"What can I say to the fans? Sorry that it didn't end up the way you expected, but it wasn't the way we expected either. That's very painful, but there's nothing we can do about it anymore and that's just the way it is.
"I don't know if it's the end of an era. It's also not up to me to decide something like that. It will be something the coach needs to do. Some players are a bit older, but one thing is clear: there's enough quality within the squad, it just wasn't shown during this tournament."
Netherlands will leave their base camp in Krakow on Monday afternoon and are expected to return to Schiphol at 17:30CET.