#1

Not entirely relevant, but I liked the trend where everybody wanted the smallest cell phone possible. For 20 years cell phones got smaller and smaller. Often being the main selling point of the phone. Then all of sudden you could watch videos on your phone, and almost overnight the trend reversed to “larger is better”

#3

2020

#5

Airship travel. These were the next, awesome way to travel long distances; in fact the spire on top of the Empire State Building was meant as an anchoring point for airships. The Hindenburg kind of put a damper on it, though

#7

3D TV

#9

Hoverboards? I remember in a span of 3 months everyone had them and showed them off and then they just disappeared.

#11

The area 51 raid.

#13

This one might be a bit obscure just because I've only ever met one other person familiar with it, but Google's Project Ara modular smartphone was looking like it could've been the end all be all of smartphones. Based off the Phonebloks idea of having a Lego-like hot-swappable module phone, the idea was that you could switch out any components of the phone on the fly. Camera, fingerprint scanner, even different quality screens. Conceptually, it really looked like it could take over the phone market, as it would lead to people not having to buy whole new phones anymore, but rather replacement or upgraded parts to a phone they already liked, thereby reducing costs and increasing utility. You don't want a phone with 5 cameras that inflate the cost unnecessarily? Just buy a one camera module. You want a 1440P Super Amoled screen to replace your 720P regular screen? Buy one and swap it in. However, like many Google projects, it died off for myriad reasons and the longstanding era of $1000 dollar smartphone slabs lived on.