It's wonderful to see Barney back, and to revisit the very special chemistry between Barney and Andy. Barney's heartbreak at Thelma Lou's marriage is truly painful for loyal viewers to see--we feel sorry for both of them. The awkwardness is palpable. We are relieved by the attentions of Nettie towards Barney and realize that Barney Fife will never stay down for long. This is one of the best episodes in the entire series--not to be missed! In fact, the series could have ended right here (although I am glad it didn't)and it would have "wrapped things up".
Barney is looking forward to his high school reunion and is anxious to see his long-time girlfriend, Thelma Lou. A few discrepancies have been pointed out about this. First, the year they graduated, was it 1948, or 1945 or some other year, as in earlier episodes? Second, why didn't Barney propose to Thelma Lou before going to Raleigh, and what made him so busy that he couldn't drop her a line once in a while? These are worthwhile questions to ponder, but they're continuity issues that nearly every long-running series has, so they shouldn't make it any less enjoyable to watch. You have to feel for poor Barn when, after seeing Thelma Lou again, she introduces her husband. Barney seemed, at this point, really in love with her, and then she drops this bombshell on his hopes and dreams. Probably most adults can can identify with this. Fortunately, another schoolgirl from the class takes a liking to him, and he gets over Thelma Lou real fast. Such situations don't always end so happily in real-life, but it's good to see it happen if only on TV. As was also pointed out, the show could have ended here, and it would have run its course well, though there were many good episodes that followed.
As good as it is to see Barney back in Mayberry, there is a bit of oddness when he first gets back. One wonders did he never call or write when he left for Raleigh? Did he really just up and leave Thelma Lou the way it seems?
The episode really gets back to its old rhythms when Andy and Barney share a porch scene and then go to the class reunion. The meeting with Thelma Lou is magical, but then what happens next is completely devestating and wrong in so many ways. Barney is crushed beyond anything that he's ever faced before. What's worse is that the writers introduce a new girl (actually an old classmate) and suddenly Barney is expected to forget all about it. It seems unfair and a shallow cheat that was only corrected in the Mayberry reunion movie twenty years later.