30 years ago was my first. The night before Christmas eve, it had been snowing for a couple of weeks before. I went out the front door about 9pm to put the empty milk bottles out. It was freezing cold, snow still about with a very stiff wind.
This ginger cat was at the bottom of my drive crying and obviously wet and distressed.
Cats are normally very shy but it didn't take this one long to make up its mind that it wanted to come in for food and warmth, it was staving to put it mildly.
It got through a whole tin of tuna in one go, didn't have anything else other than milk.
Asked about for a week or so to try and find who's cat it belonged to, was informed it belonged to someone who had moved house and had just left the cat. A few people told me it had just been walking the streets for some time.
Then I found out it was to become a mother :) it had six kittens, kept one and the others to a cats home when they were ready. 12 months later a knock on the door, have you got our cat? we want it back. oh dear!!
Had some advice from the RSPCA they said, 1. they would have to prove in some way it was their cat, and 2, you would be in your rights to present them with vet bills, food bills and care for the cat while it was in my home. That's what I told them and they didn't bother claiming it. Had the cat for 15 years.