Yesterday and today people at Barcelona and Ajax will be appalled at how they threw away three goal leads in the Champions League semi-finals. This can happen when you fail to concentrate, even for periods in games.
Imagine the taste of despair, failure and sheer waste in Barcelona and Amsterdam right now. Then consider our job against Hearts at Hampden. Hearts beat us already this season and turned us over in our own freak result last season. Winning a treble treble is rarer than Celtic reaching the European Cup Final.
Moments without concentration and it could slip away. This is why trebles are difficult and why what lies ahead of us has been impossible in the history of the game.