As well as the disappointment at club level, Messi suffered the devastation of losing the World Cup final with Argentina and saw Cristiano Ronaldo oust him to win the World Player of the Year for a second consecutive year.
“Last season, I had an inconsistent season. I was out for a long time with injuries and I missed a lot of games,” Messi told Barcelona’s website.
“When I returned to playing I didn’t feel good. It was a year I have tried to forget quickly to get back to my best with the effort, work and joy with which I have always had and thankfully now I feel very good.”
Messi has stormed back to form since this season with 45 goals in 44 games to put Barca in position for just the second treble in the club’s history.
Luis Enrique’s men lead Real Madrid in La Liga by two points with seven games to play, face Athletic Bilbao in the Copa del Rey final and travel to Paris Saint-Germain for the first-leg of their Champions League quarter-final on Wednesday.
“We went through times that we won everything, every year we would win a title and sometimes the fans and us didn’t value what we were doing,” Messi added.
“We had a bad year when we didn’t win anything and now, when the success comes, we give it the importance it deserves and we enjoy it more because we know how difficult it is to achieve.”
The one area of Messi’s game that has let him down in recent months has been from the penalty spot as the 27-year-old has missed five of his last 11 spot-kicks, including against Manchester City in the last 16 of the Champions League.
“It angers me. Both with Barca and the Argentine national team I am the penalty taker and the goalkeepers study you and know you better every time.
“It is true that a well-taken penalty is very difficult to save, but at the moment it is more difficult for me when I’m taking penalties.
“These things happen in football, but I do get very annoyed when I miss, like against Manchester City when the goal would have given us a much bigger advantage.”