Would you ask a WWII vet to describe D-Day? 
Sure.
Btw, it didn’t come up because the protagonist’s first name is spelled “Hieronymous.” My bad.
It’s pretty hard to explain. It was co-written and directed by its star, Anthony Newley. After seeing this film last year, I remember being sad that he had died, because I couldn’t track him down and kill him. It’s sort of autobiographical (Newley grew up in the theatre)… it’s so bloated and pretentious, and mostly it’s damn confusing. Parts of it are like a musical version of Lolita (Mercy Humppe is a young teen who he becomes infatuated with for some reason), other bits feature Hieronymous going on and on about how bad his life has been - most of it takes place on a beach for some reason. It’s pretentious surrealism.
If I’m saying “for some reason” a lot, it’s because 1) my brain doesn’t want me to access my memories of the film, and 2) it’s pretty incomprehensible.
Here’s the key if you want to see it (assuming you can find it, and I don’t know how you would): it’s not funny/terrible, like Plan 9. It’s really and truly terrible. It’s sort of like Manos - it just drags on. There is nothing to laugh at, like silly continuity errors. You’ll just sit there wondering what the hell is happening and why it’s happening the way it is. It’s painful. It will break your soul.
You’ll wonder why Joan Collins’s character is named “Polyester Poontang” (look it up), and why Milton Berle shows up (as “Good Time Eddie Filth”). Actually, that was one of the sole funny moments: apparently Milton Berle is more famous in the Midwest, where I go to school and saw this movie, than in NY. A Midwestern friend of mine saw Berle appear, and cried out “Uncle Miltie?! NOOO!!”
That helped get me through the night. I just looked at the running time, and I really don’t believe this movie was only an hour and 47 minutes. I can understand where a description like this would make you more curious - watch it if you must. But I really wouldn’t recommend this movie, even to someone I hate.