My very first anime was
Mahoromatic when I started watching in about 2004/2005.
My body was not ready for the kind of heart wrenching drama anime is capable of, and though in hindsight if I watched it today, I would probably dismiss it as a bad ecchi with silly attempts to be serious, but back then...
Well, lets just say my depression was on par with being dumped by a girl or something like that. It's quite funny to look back at it and question how I reacted so strongly. Even now watching the last episode can stir a bit of a reaction from me, and the OP/ED... Yeah, melancholy.