"Let your hearts rejoice"

I was reading my scriptures the other day when I came upon this phrase. "Let your hearts rejoice." I think it's something we should all remember. I think sometimes, we try to find the bad, like we just want to have something to complain about. I wonder if we just want others sympathy. but the thing is why do we need someone's sympathy? I think we should try to more often be happy. Focus on what you have.
Me, for example. I really have no right to complain about anything. I have healthy body. I'm beautiful in my own way. My biggest dream is coming true and I'm not even out of high school yet. I can write and have been blessed with determination.
I can't even complain about my flaws. Like my clumsiness. It is good for a laugh and it adds some personality.
So, I have no right to be ungrateful. From now on, I am going to let my heart rejoice.