If You Keep Making that Face, it Will Get Stuck in That Shape. The circles spell out features of the face.
17-Across. "Everyone knows that!": IT'S NO SECRET. Nose
22-Across. Mountain hiker's protection: BEAR SPRAY. Ears.
38-Across. "I haven't decided": MAYBE YES, MAYBE NO. Eyes.
49-Across. TV episodes that are mostly flashback scenes: CLIP SHOWS.
And the unifier:
58-Across. Smirking, scowling, or smiling, and what the sets of circled letters in this puzzle are doing?: MAKING A FACE.
Across:
1. Swimmer's unit: LAP.
4. "Safe!" or "Strike!": CALL.
8. Pesto herb: BASIL. Yummers!
13. Part of some sports drink names: -ADE. Hi, Lemonade!
14. California/Nevada resort lake: TAHOE.
15. Bacteria that may cause gastroenteritis: E. COLI. Short for Escherichia coli, a bacterium commonly found in the lower intestine of warm-blooded organisms.
16. Type: ILK.
19. Spanish wine region: RIOJA. Everything you wanted to know about the Rioja Wine region, but didn't know to ask.
21. Main dish: ENTREE.
25. Snow pusher: PLOW.
28. "Elder" or "Younger" figure of ancient Rome: CATO.
29. Put in the attic, perhaps: STORE.
30. Ben Affleck Best Picture winner set in Iran: ARGO. The movie Argo was based on a true story of a CIA rescue mission during the Iranian hostage crisis. The film depicts the CIA's efforts to evacuate six American diplomats who had escaped the U.S. Embassy in Tehran by disguising themselves as a Canadian film crew. The CIA tapped Tony Mendez, portrayed by Ben Affleck, to pose as a Hollywood producer to scout locations in Iran for a film.
33. Cow's milk cheese from an Alpine region of Italy: ASIAGO. Yummers! The cheese is named after the village of Asiago in the Veneto region of Italy.
37. Plant, as seeds: SOW.
41. PC pioneer: IBM. International Business Machines.
42. Military programs intended to influence attitudes: PSY OPs. Psychological Operations.
43. Remove wrinkles from: IRON.
44. Taco topping: SALSA. Yummers!
46. Scannable bars on mdse.: UPCs. As in Universal Product Code.
48. Word on a red sign: STOP.
54. Caterpillar's cover: COCOON.
56. Put into law: ENACT.
62. La Brea __ Pits: TAR.
63. "Rolling in the Deep" singer: ADELE. I know we have several Adele (née Adele Laurie Blue Adkins; b. May 5, 1988) fans here. This is one of my favorites.
64. Public outcry: FUROR.
65. Notable stretch of time: ERA.
66. As bad as can be: WORST.
67. Sulking state: SNIT.
68. Single crunch, say: REP.
Down:
1. Hibernation location: LAIR.
2. Go off script: AD LIB. Today's Latin lesson. Short for ad libitum, which means with out prior preparation.
3. Tea variety: PEKOE. Technically, Pekoe tea is not a variety, but rather a classification of tea.
4. Lion or tiger: CAT.
5. Sounds of satisfaction: AHs.
6. One who doesn't like company: LONER.
7. British pop singer Lewis: LEONA. I am not familiar with Leona Louise Lewis (b. Apr. 3, 1985), but she has an alliterative name.
8. Keg contents: BEER.
9. Receive, as a gift: ACCEPT.
10. Player who is not graceful in defeat: SORE LOSER.
11. Suffix with infant: -ILE. As in Infantile.
12. Like birthday candles before a wish: LIT.
14. Prom queen crown: TIARA.
18. Messy digs: STY.
20. 2018 and 2019 Cy Young winner deGrom: JACOB. Jacob Anthony deGromm (b. June 19, 1988) is a professional baseball pitcher who currently plays for the Texas Rangers.
23. Doesn't go: STAYS.
24. "The White Lotus" actress Parker: POSEY. Parker Posey (née Parker Christian Posey; b. Nov. 8, 1968) was known as the Queen of the Indies because she starred in so many independent films when she started her acting career. She portrayed a neurotic dog owner in Best of Show.
26. Maine university town: ORONO.
27. Cry of victory: WE WON!
29. __ sauce: SOY.
30. Just a little off: AMISS.
31. Morocco's capital: RABAT.
32. Athlete's closet: GYM LOCKER.
34. "Looking for," in classified ads: ISO. Textspeak for In Search Of.
35. Energize: AMP UP.
36. Sounds of surprise: GASPS.
39. Clean Air Act org.: EPA.
40. Yellowstone beast: BISON.
45. Ruins: SPOILS.
47. "Rah!" or "Olé!": CHEER.
49. Gear tooth: COG.
50. Idles: LOAFS.
51. Jesting: IN FUN.
52. Substance that can be holy or hard: WATER.
53. Freak out: SCARE.
55. Tech news site: CNET.
57. Lobster catcher: TRAP.
58. Gaping mouth: MAW.
59. Big fuss: ADO.
60. NPR host Shapiro: ARI. Ari Michael Shapiro (b. Sept. 30, 1978) is an American radio journalist.
61. Camp bed: COT.
Here's the Grid: