How come it's so easy to give other people advice, but when you face the same problem, you don't know what to do?

I was just thinking, ‘how do I get myself motivated?’ I realized—Hey! That question has been asked on fluther and I’ve actually answered it! How come I can provide answers that other people find useful, but I can’t apply the same ability to analyze or assess the situation when I’m the one in that situation?

I would like it if people might talk about a situation where they’ve had the same problem, and then reflect on why some of us are blind when it comes to ourselves, while we have clear sight when it comes to others. Is there anything we can do about it?

I’ve heard people say to me and others, “if it was someone else in this situation, what would you tell them?” That doesn’t seem to work for me. I don’t know if it’s stubbornness or just an inability to see myself in the mirror, but that trick isn’t helpful. What’s your advice?