Early in the film, Lenny visits one of his sleazy-looking friends at the Retinal Fetish club, who happens to be missing both legs. Lenny hands him a memory clip to view as a gift for the upcoming Y2K. Probably just another porno memory, or a generic thriller memory, right? Lenny's (leg-less, remember) friend plays the clip, and it's actually a memory of a healthy athletic male just running along the beach, enjoying the scenery and getting some attention from a hot jogger. Lenny's friend is practically crying when the clip ends.
Reaction seems to be mixed on that one. Some watchers saw Lenny's actions as cruel.
When we discover the reason Mace, against all odds, is in love with Lenny and keeps forgiving his many fuck-ups: a flashback to the day her husband murdered someone while her son was in the house, when we learn that Lenny was the cop who took care of her son and comforted him by reading comic books with him in his bedroom. It's the first point we realize there is more to Lenny than the grungy-loser persona, and a better man lurking within him that he wants to admit.