This is a favorite movie of mine. I seem to be the only person who thinks it's hilarious. I love Walter Matthau and his adorable droopy dog face and how he plays irritated. It's so funny.
This movie is about a guy who has a trust fund which would live forever if he would just spend $90,000 a year, and this was a long time ago, but he insists on spending $200,000 a year and so he loses his capital, his... He loses all his money. He becomes poor. Suicide seems the only option... until his butler explains to him that as an alternative to suicide, marriage might be considered.
You will not enjoy this movie if you take any of it seriously. It is dry and very subtle in places but funnier to me every time.