Forget your phone in an Uber? That's so 2020. Welcome to the robotaxi era, where the weirdness factor just got a major upgrade.

Uber's annual Lost & Found Index is back, cataloguing the most bewildering items passengers have abandoned in driverless cars across the country. The tally: thousands of forgotten treasures.

There are the usual suspects—smartphones, keys, wallets, passports, headphones. But then things get strange.

A set of dentures. An "I Heart Hot Dads" bag. A blue hat declaring the wearer an "Emotional Support Human." A 15-pound yo-yo. One large black marble duck. A Squishmallow. A Charli XCX poster.

Here's how to recover a lost item: open the Uber app, go to the activity tab, find your trip, and message support. If your item turns up, you can pay $15 for an Uber Courier driver to deliver it same-day, or pick it up yourself from an AV depot where the vehicles are serviced.

Uber's logged thousands of lost items in 12 months since robotaxis went mainstream, with services now running in Austin, Atlanta, Las Vegas, and Dallas. The volume alone shows how aggressively this driverless future is expanding. And riders are leaving plenty behind.

The age-old tradition of forgetting your stuff in transit remains, even in an era of autonomous vehicles.