"It's not something I pay attention to": John the vain.

As we all know, Lynn deliberately drew John with a pot belly and slumped, rounded shoulders because it irritated her that he would have aged better than she did even if she didn't have those nasty body image issues to contend with. She seems to have taken the same childish delight in making light of what her paranoid nature made her see as an attempt to make her feel bad by looking better as she did in trying to insert bathroom humor into the strip.

The reason that I mentioned this is that the most recent Sunday strip is one of the first in a series of strips in which it's hinted that while John might say that he really doesn't let his declining looks bother him, the same man who lectures Elly incessantly about how she should just stop worrying about her appearance is a rather vain person in his own right. This, I should think, stems from Rod's attempts to console her being deliberately twisted into something like "Stop worrying and accept you're ugly! You're married so should stop wanting to look good!!" You'd have to be a fiend to say that and, well, John IS that fiend.