Adult Sheldon (VO) in “Unfinished Business”

As long as humans have been on Earth, they've had to contend with viruses. And as long as I've been on Earth, I've come up with fun ways to avoid them. I've heard so much about you. Apparently not how I feel about shaking hands. I wear personal protective equipment. You come here right this instant. And I was social distancing before it was cool. But in the early '90s, a new type of virus became prevalent, one that no amount of handwashing could stop.