After Saturday's 1-0 defeat by Wales, Northern Ireland are leaving Euro 2016 with a nagging, frustrating feeling they did not make the most of what might be a once-in-a-lifetime opportunity.
Having qualified for their first major finals in 30 years, they succeeded in reaching the knockout stages. That is a fine achievement for an unfancied team that was in pot five when the qualifying draw was made back in February 2014.
But the fact their elimination came at the hands of Wales will rankle. Not world champions Germany, hosts France or holders Spain, but Wales, a team one place below them in the Fifa rankings.
That it was down to an own goal from the otherwise excellent Gareth McAuley strengthens the anguish.
Once again, Northern Ireland's superb fans stayed on in the stadium, singing themselves hoarse as they had done from well before the game, and manager Michael O'Neill and his players will thank the fans for their brilliant support at a public event in Belfast on Monday.
However, they will do so disappointed that they lost three of their four matches in France.
What now for manager O'Neill?
Northern Ireland's next competitive match is on 4 September when World Cup qualifying starts with a trip to the Czech Republic. Having signed a new four-year contract, it is expected O'Neill's hand will be on the tiller.
However, having won admirers on the big stage of a major tournament, will an English club make O'Neill an offer too good to refuse?
The 46-year-old's previous managerial experience was with Brechin City and Shamrock Rovers, but his stock has risen with an enhanced reputation as an astute tactician who gets the best out of limited resources. Against Wales on Saturday, for example, his decision to play wing-backs cancelled out a lot of the opposition's attacking threat.
O'Neill said during the tournament that if a job offer came up, he would evaluate it, although he added he is happy in his role.
"Michael has rejuvenated the team, got the players onside. None of them are crying off with injuries now," said Hibernian manager Neil Lennon, a former Northern Ireland skipper.
"Northern Ireland have held their own at a major tournament and to top what Michael has done is going to be difficult."
The legacy of Euro 2016
O'Neill believes the 23 players in his squad will have benefited from the experience of being at Euro 2016.
Assuming he remains in charge, he must now ensure all his key players are on board for the World Cup qualifiers against holders Germany as well as the Czech Republic, Norway, Azerbaijan and San Marino.
During Euro 2016, he cited the example of Portugal defender Ricardo Carvalho who, at 38, is the oldest outfield player at the tournament.
O'Neill said he would be using that when persuading 36-year-old defenders Gareth McAuley and Aaron Hughes to carry on for one more qualifying campaign.
Skipper Steven Davis is 31 and most of the other players are in their mid to late 20s, so O'Neill's resources appear to be healthy.
But they are in a difficult qualifying group - with only the top side certain of qualifying for Russia in 2018.
"The players have not got long to mull over what has been a fantastic time, get a break, pick themselves up and go again," added Lennon, who is at the tournament as a BBC pundit.
"Whether we can make another tournament remains to be seen.
"A lot of revenue has come in because Northern Ireland got through the group stage and that money has got to be used in the right way.
"There has to be an infrastructure in place under Michael O'Neill and Irish Football Association elite performance director Jim Magilton.
"Hopefully, the benefits will be seen in four of five years' time."
Going by recent results, it may take time for really promising players to come through and strengthen the senior team. Two young players with Irish League clubs, Linfield's Paul Smyth and Joel Cooper of Glenavon, were brought out to train with the senior squad in France, an experience which will boost their prospects.
But Northern Ireland have just one point from six qualifying matches for the European Under-21 Championship and are bottom of their group.
A tournament to treasure
There were good moments to cherish from Euro 2016, fond memories to treasure.
The victory over Ukraine which was celebrated in the midst of a thunderstorm on a never-to-be-forgotten night in Lyon.
The backs-to-the-wall defensive display against Germany, and goalkeeper Michael McGovern's part in restricting the defeat by the World Cup holders to 1-0.
McGovern, who was chosen as the outstanding goalkeeper of the group stage by both Opta and BBC readers using the team selector, is out of contract at Hamilton Academical and veteran defender Hughes is without a club. They are among the Northern Ireland players likely to reap rewards from major tournament exposure.
NI played well for parts of the last-16 match against Wales, but the lack of cutting edge and firepower ultimately proved their downfall.
And there were the Northern Ireland fans whose amazing support of their team won them many admirers and lit up stadiums in Nice, Lyon and Paris. Thirty minutes after losing to Germany at the Parc des Princes, the green-shirted fans were still singing their heads off in the stadium.
Former midfielder Lennon, who won 40 caps, added: "The fans have been incredible. They have been starved of these big occasions and Northern Ireland have covered themselves in glory both on and off the pitch."
The Northern Ireland squad will receive an official homecoming in Belfast on Monday evening.
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