Continuity mistake: The length of Sgt. Carter's career in the Marines varies from 14 years to 18 years.
Continuity mistake: The Marine Captain is showing Gomer Pyle how to salute. When she salutes she has a watch on her right wrist, but when she is shown holding the salute the watch is not on her wrist.
Gomer and the Dragon Lady - S1-E8
Continuity mistake: Sgt. Carter and two buddies are drinking beer in mugs. The "Dragon Lady" flips a man - he hits the table and knocks over a beer bottle and a beer mug on to the floor. When Sgt. Carter and his buddies go back to sit at the table all three beer bottles and mugs with beer are back on the table. (00:06:00 - 00:07:00)
My Buddy, the War Hero - S1-E25
Continuity mistake: Jimbo, Sgt. Carter's buddy breaks a chair in two with a Karate chop. Jumbo prepares to chop the chair with his right hand. When the chair is shown being chopped it is done with the left hand. (00:08:00)
My Buddy, the War Hero - S1-E25
Continuity mistake: When the chair is karate chopped in the closeup it is completely broken. In the next full frame shot the chair is shown just without the seat. (00:08:00)
Supply Sergeants Never Die - S2-E6
Continuity mistake: The Supply Sergeant Singer's second shirt button is buttoned as he approaches the counter, but as he continues around the counter it's not, then it's buttoned up again. (00:25:00)
Continuity mistake: While Gomer shows a little girl how to play jacks with sugar cubes, the number of sugar cubes go from 4 to 6 while the girl plays. (00:10:00)
Continuity mistake: Sgt. Carter's second button down on his shirt is unbuttoned. In the same sequence of Sgt. Carter talking with Gomer, the button is done up. (00:03:00 - 00:04:00)
Gomer, the Beautiful Dreamer - S4-E5
Continuity mistake: Sgt. Carter and Gomer arrive at Miss. Bunny's in Sgt. Carter's red car, but Sgt. Carter's red car was demolished by a wrecking ball in Season 2 Episode 13: Gomer Minds the Sergeant's Car. (00:07:47)
Gomer and the Queen of Burlesque - S4-E21
Continuity mistake: Gomer is on a date - they come out of the movie theater and it's dark. Back at the base after his date Gomer runs into Sgt. Hacker, and it's daylight and the sun is shining. After their brief conversation Gomer tells Sgt. Hacker good night. (00:07:00 - 00:08:00)
Gomer and the Queen of Burlesque - S4-E21
Continuity mistake: On the company road on the base, the background changes from day to day. First there are white houses and trees, then the next day there are no houses, just trees and telephone poles. (00:09:00 - 00:19:00)
Friendly Freddy, the Gentleman's Tailor - S4-E30
Continuity mistake: Gomer's suit has one button but after he has the suit dry-cleaned the suit shrinks and gains a button to be a two-button suit. (00:09:36 - 00:17:43)
A Little Chicken Soup Wouldn't Hurt - S5-E10
Continuity mistake: While Molly empties all the homemade food from her black bag onto Carter's desk and then the men eat, Molly's purse is either hanging from her left arm or it's gone, depending on the camera angles.
Answer: If you saw the whole series run, you know that Gomer was a country bumpkin. He fumbled, stumbled and tumbled his way into one disaster after another. There was an episode that questioned why he was never promoted. However, a few years before Jim Nabors died, the real Marine Corps, gave him a ceremonial promotion to the rank of Lance Corporal, which Jim gladly accepted.
Unfortunately, I never saw all the episodes. Only a few episodes and a clip of the episode where he sings "The Impossible Dream" which made me wonder why he was still a PFC. Thanks so much for the info.