Collections range from rich to weird

Clutter enemy Marie Kondo recommends tidy living, surrounded by just those items that spark joy.

For Jay Leno, cars spark joy. He has 136, along with 90 motorcycles, worth about $50 million.

Jay Leno has a collection. We know this because he isn't out buying cars and dumping them to rust in an old field. And he can afford it. But, is it still kind of weird?

According to British researchers reporting in 2012, about one-third of the population of Western countries collect something.

But what is it about back scratchers that prompted Manfred Rothstein to collect 675 of them and by 2008 achieve the world record number?

Maybe we should ask Petra Engels who has the world's largest collection of more than 19,000 erasers. Or Niek Vermeulen who has more than 6,000 airline barf bags, unused. Maybe we can understand collecting Barbie dolls or even troll dolls, but what about toenail clippings (really) or traffic cones?

Ever since humans settled down 12,000 years ago and gave up their nomadic ways, collections became possible. According to invaluable.com, collectors in the 19th century used their curiosities to highlight their wealth and travel.

Collectors, says Randy Frost, professor of psychology at Smith College, assign special value to specific objects.

A collector goes to a lot of trouble to maintain and display a collection. Well, unless you are Niek Vermeulen and then you just stash the barf bags in a box under the bed. But most display.

Collections don't have to involve expensive cars. They just involve things the collector feels passionate about.

The key is that collections are organized and they don't start taking over the house in piles. Cross that line, and you don't have a collection.