PERFECT days in football, like the one Celtic enjoyed under the scorching sun at Hampden in May 2001, are few and far between.

Setbacks usually outnumber successes, and even triumph can quickly evaporate in the face of change, which is why Neil Lennon will tell his team at 2.45pm today to seize the moment.

The Celtic manager knows only too well that Scottish Cup finals can become a last act for players and managers. If the memories of defeating Hibernian 3-0 all those years ago, to seal a treble under Martin O'Neill are easy to recall, it is because it was a perfect day which left a lasting legacy.

The same could be said of the 2004 final against Dunfermline Athletic, which brought more sunshine, a double and goals from Barcelona-bound Henrik Larsson. A year later, though, Celtic lifted the Scottish Cup in the rain against Dundee United, weather which matched the mood, of an occasion few – including Lennon – recall with affection. O'Neill had just announced he was leaving and the title was lost at Fir Park. Jackie McNamara, who held his testimonial the day after the final with United, never played again for Celtic and was pushed out of the door. Even Lennon succumbed to the Hampden curtain call. The 2007 final was his last game as a Celtic player.

He captained the side to another victory over Dunfermline and led Gordon Strachan's team to another double – although he was famously substituted – but when Lennon took off his Celtic top in the Hampden dressing room, the next time he put on a football shirt it was the red one of Nottingham Forest.

"The 2007 final was my last game and I have happy memories of that," reflected Lennon. "It was a nice way to finish my career." Even being hooked after an hour by Strachan? "I was crap," laughs Lennon. "It was the right call, I suppose, because we ended up going on to win. I was a bit emotional because there was a lot going on at the time, but looking back, it was brilliant. Winning the double in your last game is the way you want to go out. Now, I can see you take it for granted and we are trying to make sure the players do not do that because these days and these moments do not come around very often. This could be the last time this team are together, for one reason or another, so it would be good for them to leave a legacy behind them."

If Lennon is referring to the potential sale of Gary Hooper or Victor Wanyama to England this summer, then only Hooper will have the chance to sign off with silverware because suspension has denied the Kenyan his big day.

However, despite speculation about taking over at managerless Everton, Lennon does not appear ready to inflict the sort of body blow on his players that O'Neill did just before the 2005 final when he quit because of his wife's health.

"I thought we did well to get through that week," Lennon said. "Given how sore and disappointed we felt after losing the title then that was compounded by Martin announcing he was leaving. It was a tough week.

"We won [the cup], but we won't have many fond memories about it because ultimately, the league's the priority. However, going into the final, you want to win. There's the chance of a double, this team deserves that. We've been knocking on the door for a while, winning a trophy each season, but it would be nice to get two in the bag."

Indeed, while Lennon is stalked by the issue of a Hampden hoodoo because of several high-profile defeats there, this is his fourth final in three years, plus three appearances in the semi-finals. Where others see discredit in failing to maintain a 100% record, Lennon sees disrespect towards Hibernian, Kilmarnock or St Mirren.

"I get disappointed with people who say we should win everything. It's disrespectful to everybody else," he said. "These guys are professionals. Football means everything to them. We will have 14 players doing everything they can to stop us winning the trophy."

He needs only to cast his eyes towards Wembley and the Bernabeu to find proof of the underdogs that bite. Manchester City and Real Madrid were big favourite to win the FA Cup and Spanish Cup finals, but fate decreed differently. "If we need a warning sign, that's it," Lennon said. "Wigan were brilliant. That performance was one of the biggest shocks in FA Cup final history. I watched the Spanish final and Real hit the posts three times, but it was Atletico Madrid's night."

Lennon will hope that this green day at Hampden is Celtic's.