It's a clever little plot: Gru, a villain with a perpetual smirk, is going about his everyday life – doing rude things like making an animal balloon for a crying child, then popping it – when he hears on the news that someone has stolen the Great Pyramid of Giza. Concerned that a new villain is stealing his thunder, he reveals to his minions a plan that will make him the greatest super villain of all time: shrink and steal the moon.
He approaches the Bank of Evil to get financing for his project but is told by the head of the bank that the bank rarely sees a return on his investments. He must obtain his own shrink ray to show the viability of his project. Just as Gru is about to steal one from a laboratory, the same culprit behind the Great Pyramid theft beats him to it.
Spying on Vector, the nerdy villain-wannabe whose name is really Victor, Gru discovers his weakness for chocolate chip Girl Scout cookies. Determined to infiltrate Vector's hi-tech fortress, he adopts three adorable Girl Scouts, and as can be expected with any kids' movie, they grow on him and he grows into his role as father to three girls.
Personally, the best thing about animated movies is that they employ fanciful events to foster real emotions and personalities. How many thick-skinned individuals have fallen in love despite their better judgement? It happens everyday; it's just more fun in 3-D.