Exactly. I think those people just feel good and that's it, without going further analysing why they feel that way (good). I mean, they don't start thinking "Oh let's see, I feel good because I have support, care, love and appreciation from these people; they love me, so I feel loved, and so I feel good because of that". They JUST feel fine, and they may believe it's only due to them, "because they love themselves". And here comes one of the biggest platitudes then: "If I can do it (love myself in this case), you can too!" And the cycle begins again.
I've never seen or met a person who felt good, happy (at peace with themselves) that didn't have a supportive family and/or friends, and fulfilling relationships with others. But they don't see it, don't acknowledge it and don't think about it, they just feel it. And they may believe that good feeling is emanating from them, the others don't have anything to do with it. So wrong.
It's something that really bothers me, how they are so oblivious to how positively influenced they are by external love. And that you can't love yourself without being loved by others, that's pure and true psychology. "You don't exist unless you're seen by others". We're human, we're social, we need love.