The first Popeye cartoon I watched was one of Larry Harmon's TV Popeye's, "Mussels Shmussels", and I didn't see it from the beginning. I had never heard of Popeye at this point. Popeye has fallen a great distance and has done the cartoon cliche of leaving a hole in his shape. Brutus fills the hole with quick-drying cement. But he couldn't stop there. He flings a trowelful of cement right in Popeye's face, which pushes Popeye over the edge. He shakes his head until the cement comes off. Then he shakes his head again until his hat flies off, revealing a can of spinach underneath. Popeye inhales the spinach through his pipe. An earthquake starts and the concrete starts cracking. Freed from his concrete prison, Popeye beats the crap out of Brutus. I loved it. I've been a victim of bullies my entire life, including being bullied by members of my family. So I loved seeing a bully get what he deserved.
I'm guessing that it was when I was in the third grade, because when we had "brawl" as a vocabulary word, the teacher told us "Popeye and Brutus brawl all the time.". That would date it to the fall of 1975. (I remember seeing commercials with clips from the 1960's TV Popeyes on what was then Tampa's only independent TV station, WTOG 44, before the cartoons started airing. But no eating of spinach.)
The first theatrical Popeye cartoon I saw was "The Anvil Chorus Girl" , on Miami's WCIX while visiting my great grandmother who lived in Fort Lauderdale. I didn't notice the difference in quality at that age but I wondered why Brutus was being called Bluto, and why he was wearing a white sailor suit like Popeye's. The first Fleischer Pooeye cartoon I saw was "Protek the Weakerist", while visiting an aunt and uncle who lived near Atlanta. I saw more of the color cartoons from the 1940's and the 1950's on one of Greeneville, Tennesse's local TV stations, 13 WLOS, while I was at Tusculum College. (They were even introduced by a host.) But it took the Turner networks for me to see most of the rest of the theatrical Popeye cartoons, with a handful of "politically incorrect" ones coming from other sources, including a member of the TTTP. (I traded my uncensored VHS recordings from WTBS and TNT for those last ones.)
In July 1979 I bought the book Popeye: The First Fifty Years by Bud Sagendorf, who was E. C. Segars assistant from 1931 until Segar's death in 1938. He wrote and drew the Popeye comic book from 1948 until 1967, the daily Popeye comic strip from 1958 until 1986, and the Sunday Popeye comic strip from 1958 until his death in 1994. I crudely printed my name and the date of purchase on the inside front cover. Tucked inside are newspaper clippings about Popeye going back to 1979. In 1994 Bud Sagendorf was a patient at the hospital where my mom worked, so my mom took my book in to work and he inscribed it to me. (Even though the book was falling apart by then.) That book is one of my prize possessions, along with my copy of the revised edition of The Fleischer Story that I bought new in 1992, which was inscribed to me by Myron Waldman when he was a guest at an animation art gallery in Tampa's Hyde Park district in 1993.