Greek philosopher Epictetus once said ‘it is impossible to begin to learn that which one thinks one already knows’. Mikel Arteta and his Arsenal side showed they have plenty to learn after crashing out of the Europa League at the hands of Olympiacos. Islington Gazette Arsenal reporter Dan Mountney takes a look at the harsh lessons the Gunners must heed.

Arsenal's defeat essentially came down to one thing, poor game management.

With a 1-0 lead from the first leg in Greece the hard work looked done for Arteta's men, but a performance lacking tempo and energy saw Olympiacos take full advantage by snatching the win right at the death.

Arsenal looked unsure whether to stick or twist on their aggregate lead and their lack of game management cost them dearly.

Despite the good start to his reign, Arteta's inexperience in situations such as the one the Gunners found themselves in was clear and it will be a lesson he learns from.

Crashing out of the Europa League is a major blow to their season but it could help Arsenal and their boss in the long-term.

While Arteta has plenty to learn, so do the players who simply failed to see out the game in the dying minutes.

Pierre-Emerick Aubameyang's overhead kick in extra-time put Arsenal ahead in the tie with just seven minutes left to play, and at that point, they should have been able to see the game out.

A poor back pass from Granit Xhaka, a terrible clearance from Bernd Leno to give away a corner in the dying seconds and a lack of focus from David Luiz and Sokratis all contributed to Youssef El-Arabi scoring the goal that dumped the hosts out.

It was a completely avoidable goal that never should have happened and highlights a lack of situational awareness.

When the ball should have gone deep into the Olympiacos half and then into the corner, the Gunners failed to clear it out of their own third.

Arsenal must not become a slave to the style that Arteta wants and adapt to what is happening around them.

There must also be less of a reliance on Aubameyang, who looked like he had the weight of the world on his shoulders when he turned a shot wide in the final seconds of the game.

The Gunners have turned to the Gabonese striker far too often this season and with his future up in the air, those around him need to step up and take responsibility in difficult moments.

The Europa League exit is a big blow for Arsenal, but they must turn the negative into a positive and learn from their mistakes.

It was clear when Arteta was appointed that it would be a long-term project and the disappointment at the Emirates on Thursday night highlighted that plenty of work still needs to be done.

It will be difficult for the Gunners to lift themselves again, but as Epictetus once wrote: "Difficulties are things that show a person what they are."