The Reds were holding on to a 2-1 lead against Southampton at Old Trafford when Michael Obafemi plundered a 96th-minute equaliser for the visitors.
The goal keeps United in fifth place, despite extending our unbeaten run to 18 games, ahead of the crucial run-in.
Ole believes the players will learn a harsh lesson from not seeing the match out but it will stand us in good stead for the challenges to come.
On Thursday, there is a chance to quickly bounce back, at Crystal Palace, before Sunday's Emirates FA Cup semi-final with Chelsea. On the following Wednesday, our home domestic campaign ends with a clash against West Ham United with a trip to top-four rivals Leicester City marking the end of the Premier League season on 26 July.