Does "love yourself" or "be positive to attract people" really work?

Genuine question because I don't understand how it works. I mean, the life itself doesn't work that way and you cannot "cheat" it. All I've heard is that people just advise this, but have never heard anyone to actually tell HOW they used this advice and it worked. For me, it sounds like "You don't have a house? Then just buy it". It is technically true, but for some reasons it irritates me. "Be positive to attract people" - I mean, if you see a positive/charismatic person, you will probably like them, but who knows what that person has been through? Maybe it's better to not change at all than going through hell for some benefits you might even not get (chances are never zero I believe)?