WTP, it’s not really proportional. When I was 20 years old, I did not think that 20 year old guys were old. Now that I am not 20 anymore, I do think that guys my own age are old, but I know that I have no choice but to marry someone old and I’d just prefer that they not be too old.
Funny story about that: (I don’t remember the exact ages in the story, so I will approximate): A friend of mine suggested a 40 year old to me. I responded, “Wow, that’s so old!” Meanwhile, I had completely forgotten that I was 35 years old, and momentarily thought that I was 25 years old. As soon as I remembered my age, I realized that 40 was not too old for me. Meanwhile, my friend probably thought that I was very picky!