Love and loss.
Romance and heartbreak are two more vital human experiences. You might be better off without the latter, but if you haven't been through both you just haven't lived the human life.
In one of his most remarkable and exposing public moments, Danny actually told his ex-wife that he loved her. Shirlena has appeared in several videos. Sometimes their encounters were hostile, but it's clear that she reciprocated his love in some way. His former significant other, or at least the woman who plays her unconvincingly, frequently poured her heart out to him.
Interestingly, even though Shirlena is a lot closer to a "normal" person than Danny, she needed him more than he needed her. The world is full of assholes, and she must have decided that she'd rather spend time with an asshole that was honest and not really an asshole. Why they never fully reconciled and got back together is uncertain, but they seemed to have worked out their relationship to a point at which it was most comfortable.