If you watched Season 1 of “Stranger Things,” it was probably because someone told you to.

The series didn’t get a big push from Netflix. It wasn’t pitched to TV critics. But when it debuted in July 2016, “Stranger Things” caught on. Netflix doesn’t release viewership numbers, but clearly a lot of people were talking about it and writing about it.

With good reason. The eight-part story, set in 1980s Indiana, played out like a 1980s horror movie. It centered on the strange disappearance of 12-year-old Will (Noah Schnapp); the efforts of his friends Mike (Finn Wolfhard), Dustin (Glenn Matarrazo) and Lucas (Caleb McLaughlin) to find him; and the arrival of a strange girl, Eleven (Millie Bobby Brown), with strange powers.

It was clear to anyone who watched that there could be a Season 2. The mysteries of Will’s disappearance and Eleven’s appearance are solved, “but then there’s a bigger mythology behind what happened,” said Matt Duffer, who created, wrote and directed “Stranger Things” with his twin brother, Ross. “There’s definitely a lot of dangling threads at the end.”

Threads that are picked up and woven into Season 2, which starts streaming Friday … behind a monthslong advertising campaign now that Netflix realizes what it has in “Stranger Things.”

If you haven’t watched Season 1, should you?

Yes. It’s only eight episodes, which run a total of 6½ hours, so you could binge it in a weekend. And it’s fun. Scary. Engaging. The young cast is outstanding.

You shouldn’t deny yourself the viewing experience.

But if you choose to just jump in to Season 2, you won’t be lost. “Strangers Things 2” spends a lot of time in its first few episodes resetting the stage by re-establishing everything that happened in the first season, which serves to slow things down somewhat.

Once things get going, Season 2 is more tense, more frightening, more exciting and more disturbing than Season 1. No spoilers, but things pick up a year after the events of Season 1 and the characters are trying to get back to normal … which we all know is not going to happen in the nine-episode Season 2.

ANOTHER UNEXPECTED SUCCESS • The Oct. 22, 2016, episode of “Saturday Night Live” featured a weird sketch with Tom Hanks as David S. Pumpkins, a guy wearing a suit made of cloth with a jack-o-lantern pattern, and Mikey Day and Bobby Moynihan as skeleton dancers. It wasn’t all that great, and it didn’t seem to get a big reaction from the studio audience.

But it became A Big Thing on social media, and now it’s an animated Halloween special (Saturday, 10:30 p.m, NBC/Ch. 5).

It hasn’t been screened for critics, so you’re on your own.

FOR CHILDREN? • To me, it’s off-putting to produce “Michael Jackson’s Halloween” (Friday, 7 p.m., CBS/Ch. 2) — a special that features an animated Michael Jackson and is aimed at children.

Ick.

This also has not been screened for critics.