Maimonides does not take this too literally but thinks it means that one should drink enough wine to fall asleep. Those who like gematria (the calculation of the numerical value of letters) say that Arur Haman (“Cursed be Haman”) and Baruch Mordechai both add up to the same number, 502.
But there must be more to it than that. A feature of the Pesach Haggadah may indirectly suggest an answer. In the four sons, the wise is followed by the wicked, then by the unsophisticated son and the one who knows not how to ask. All but the wicked are judged by their intellect, the wicked by his ethics. The wise and the wicked are both clever, more or less on a par intellectually, but one is ethical and the other is not. They are reverse images of each other.
Similarly, Haman and Mordechai may be seen as reverse images of each other. They have things in common. Neither is a Persian: Haman is an Agagite and Mordechai is a Jew. Both are elevated to power as a result of events which they more or less engineer. Indeed both enjoy their power; at the end of the M’gillah the Jewish people’s praise of Mordechai is muted though the comment that he was “acceptable to most of his brethren” to most, but not all, because some did not approve of what he had become.
But what differentiates Mordechai from Haman is that the latter tries to impose a sameness on the whole kingdom, with zero tolerance for difference and diversity. Mordechai does not insist that everybody give up their individuality. His power is used in order to draw the best out of every citizen. So Haman and Mordechai are similar, but in what really matters they are world apart. Only when you drink too much and lose touch with reality do you fail to see the difference.
Maybe, for one day only, you are allowed to get merry and show that even good leaders like Mordechai can be laughed at, but by the following day you have to put the right standards back in place.