I dont know if you have played football or are a fan, but the context is a great part of the difficulty of a goal, not only were his opponents better the stakes were sky-high. Players who regularly score in a normal game freeze when the do-or-die time comes. For all his brilliance Messi has never scored a goal in a decisive game in a WC, Maradona scored 4 in 2 games in 1986.
And there was that moment Messi skied a penalty kick in ... what was it, the Copa América final? He announced his retirement the day after. Of course, retracted.