Two good points of interest here in what otherwise is a TZ to forget.
One is that Richard Matheson has put a darker spin on a theme that Rod Serling used several times. The wish to return to childhood happens in 'Walking Distance', 'Kick The Can', 'Horace Ford', with variations of this theme elsewhere in the Zone. This time is different because we see this story through the wife who becomes fearful of her husband slipping away.
The second point of interest is Phyllis Thaxter in the role of the anguished Virginia trying to finally claim her husband as her own. The thinner plots in TZ were often held together by the lead actress. This minor star (to be found in a few Alfred Hitchcock Presents) provides a very sympathetic character and was always so expressive and watchable. The mother-in-law was clearly no monster, but for the sake of sanity we side with poor patient Virginia. Husband Alex (Alex Nicol) starts to act weak in a real creepy manner. Come on Virginia ! - but what's the girl to do?