When you room with Ronaldinho, you’ll never forget it.

In January 2001, Mikel Arteta, then 18 years old, arrived at Paris Saint-Germain by himself and was “terrified.” He had been sent there on loan from Barcelona’s famous La Masia school for 18 months.

Mikel Arteta has lifted the lid on sharing a room at PSG with RonaldinhoCredit: Offside/PRESSE SPORTS

The Arsenal boss is looking to get the better of his old side in the Champions LeagueCredit: Getty

Mauricio Pochettino, an old friend and mentor, showed him the ropes on his first game of adult football for men. Pochettino was the one who first made Arteta want to become a manager.

Arteta learnt more about the beautiful game from Ronaldinho, a 21-year-old Brazilian player who moved in with the now-Arsenal manager in the summer of 2001.

Arteta meets the Parisian giants for the first time as a manager on Tuesday. He can’t help but smile as he thinks about what it was like to share a room with a football legend who was known for his tricks and flair on the pitch and his crazy partying life off it.

Ronaldinho went on to become a Barcelona and Brazil iconCredit: Getty

Arteta also played with Bolton legend Jay-Jay Okocha at PSG

When asked what kind of flatmate Ronaldinho was, Arteta said with a smile, “He was always perfect with me.”

“We lived together for a year.” He was great. Lots of life and fun; everything was fine. Not a problem at all. Fun times.

“Of course, I didn’t think of him as a superstar at the time.” But he had a lot of skill.

“He was from Brazil.” He had to wait for a few months because he didn’t have the work permit.

Arteta wanted to stay in Paris after his loan spell ended, but Barcelona called him back and sold him to Scottish giants Rangers in 2002. He then came to England through Real Sociedad and joined Everton two and a half years later.

Ronaldinho’s time at the Parc des Princes was also short but sweet. He left for Barcelona in 2003 and won the Ballon d’Or, two La Liga titles, and the Champions League in five years there.

Arteta went on, “He’s the only player I’ve ever seen who could change two clubs by himself.” It was in Paris, where he changed them. He went to Barcelona when things were going badly and made things better.

“He was charged with energy and had a smile on his face. It was impossible to be unhappy around him.”

“And when I was training, I never saw such a skill.” It was like, “How is this possible?” during every drill.

“It was crazy fun to play with him.” Because Ronaldinho and Jay-Jay Okocha were in front of me, I had to do all the defence. Think about it!

It was so cool it was almost unreal. For me, it was a dream.

“I felt so lucky and full of energy at that time.” I couldn’t miss that chance, and I loved every second of it.

Arteta is also very close with Luis Enrique, the 54-year-old former Barcelona player and manager who won the treble, and they have a lot in common.

But Arteta, who is now 42 years old, says that his time in Paris, where he was “protected like a son” in the “perfect environment,” made him into the man and manager he is now.

An unknown youngster joined a month later, and his first Champions League game was at the San Siro against AC Milan. It ended in a 1-1 draw.

For Arteta, it was Silvio Berlusconi, Paolo Maldini, and Andriy Shevchenko who he saw while he was in the tube looking.

“I looked, and they were all like this” (puts up his hand). “Really?” I asked myself. In Rome, I was thrown to the dogs.

“But it turned out to be a great match, and I loved it.” What a crazy night it was.

Arteta hopes for another night like that at the Emirates. Their first Champions League game ended in a 0-0 draw at Atalanta last month.

Last year, Bayern Munich beat Arsenal 1-0 in the second leg at the Allianz Arena on April 17, knocking them out in the quarterfinals.

Three days before, a 2-0 loss at home to Aston Villa hurt their chances of winning the title.

He said, “Last year we almost went all the way.” This year’s title race and European run will be even tougher. We failed, so we need to do better in that area to show that we can do it. That’s what we need to do next as a group.

Defendants Riccardo Calafiori (knee) and Ben White (groin) will have late fitness tests.