What does 'vintage' mean?

This is a hard one, here's why...

A clear age for vintage is not defined. You'll find different answers everywhere, including dictionaries and the experts in the field of vintage and antiques. 

These are my thoughts being a collector and having some expertise in this field.

My rule of thumb is 20 years back. But, and here lies the issue, vintage to me and most collectors is a feeling. Take for instance, a doll I adored when I was just a girl, her name was Chrissy. If you pushed in her belly button, her pony tail would grow (kinda weird thinking about it now, but not the point), the point is, I was 4 at the time, and not to give too much away, but that was over 40 years ago.

That would make this antique in age by many measures, but will never be to me because of its sentimentality. It 'belonged' to me, and gave me joy, so when I reflect on it, I don't think antique, I think about how it made me feel, and this to me is vintage.

But then there is the marketplace, and they do use age as a factor, using 20 to 25 years old in most cases, Places like Etsy, where sellers are showing appreciation to the items quality by labelling it vintage, are where this most commonly applies.

So now, a warning! The word vintage is very often used incorrectly by the marketplace, when really what a seller is trying to express is their item is retro, modern, or even just something that has been used.