I kind of had similar relationship...
Someone recommended me years ago to see this movie after she found about my unusual relationship and I finally seen it yesterday on Netflix.
So here's my story in a nutshell: I was suicidal since age 12, and despite my above average intelligence & looks never slept with anyone until I was 23. Then I finally slept with a woman exactly twice my age. She was bipolar, so in a way she resembled Maude. My mother was horrified when she found this out (I was the only child). Especially, when I was contemplating to marry her & even attempt to have children with her!
Now, while I was suicidal, I was much more talkative & joyful, than Harold, & my "Maude" wasn't nearly quite as philosophical & innately intelligent as Maude.(Although she was very free spirited & spontaneous, not to the point of braking the law, though. And loved decorations & plants.) So the comparisons can go only so far.
Anyway, the complicated romance lasted for almost two years. And, I haven't known any woman since (I am 29 now). Nor, I have much desire to know other women, or other women have desire to know me (I am not nearly as wealthy as Harold).
But that's life, and I would rather live vicariously through lives of others in the movies I watch. It's less complicated that way, and I am still too emotionally vulnerable to establish serious relationships. A bad romance, can be literally life threatening for me (despite my current anti-depressant medications and the pets that keep me alive).