The Barcelona star announced his retirment after Argentina suffered a penalty shoot-out loss to Chile in the 2016 Copa America final.
However, head coach Edgardo Bauza managed to convince Messi to change his decision and the forward helped Argentina secure a spot at the 2018 World Cup.
"It was a decision I made in the heat of the moment, but I was embarrassed to say I wanted to come back," Messi told DIRECTV Sports.
"El Paton [Bauza] and my team-mates made everything easier for me to return."
Messi added that he is now more relaxed when it comes to dealing with pressure for the national side.
"At 30 years old, I enjoy it in a different way and much more than before," he added.
"I take advantage of every moment, both on and off the pitch. I am experiencing this moment with the national team in a different way.
"I am more relaxed today. When they criticise me, I experience it differently."