Smoking everywhere. For anyone who wasn’t around for the 70s/80s/90s, everything was tinged yellow and smelled of smoke. Car/plane/train seats had built-in ashtrays. Restaurants had smoking sections separated from the non-smoking sections by waist-high walls.

I have asthma and it sucked. Not sure if I grew out of it as I got older or if there’s just not a miasma of smoke around everywhere, but it rarely bothers me anymore.