Who is criticism and/or unsolicited advice easier to take from? Criticism is never easy to hear, but I think there are ways it is easier to digest than others. For example, is it easier to hear from a "fluffy" person that you need to lose weight, or someone who is either thin or has "conquered" their weight problem? Is it easier to hear how to raise your kids from someone who has never had children of their own or someone who has raised a gaggle? How easy is it to hear a messy person comment on the cleanliness of your house?
For me, it is much better received to hear information from someone who has actually lived it. I saw something on TV yesterday about Kirstie Allie creating a weight loss program of her own and the commentator mentioned that it might have a hard time being successful if she is still battling her weight. (Don't laugh at me, I was watching ET) I used to be really bad about giving other people advice or correcting other people's children. Before I had kids, who was I to comment on what you were doing with your kids? Now that I have my own and someone who doesn't have kids comments on how I am raising mine, it really rubs me the wrong way. Yes, I agree, in theory, you should not let your child have M&Ms before dinner, but sometimes, when you are in a public place and it isn't worth the fight over a couple M&Ms, you let them have it. When you don't have kids, you don't understand the unconditional love and that sometimes it just isn't a battle you are willing to pick at that time!
I think that criticism and/or unsolicited advice is tricky. You have to know how to present it and when to just keep your mouth shut. As the receiver, you have to know when to take it under advisement, when to tell the giver to shut it, and when to let it just roll off your back! And THAT is much easier said than done!