Well not all of them may be true, you have to see the context of how you can apply it. For example this one that you have in your card, it's a bit confusing ^^;, but basicly, what I think, it's saying to not mind what others say (or think) to you, and you not doing the same thing to others. You can take the quote and apply in a positive way or in a negative way. Since its a 'tip to stay happy' in this quote, its for something good you do for others so that you stay happy ^^.

Well, hope I gave my explanation across clearly XD; ^-^;

~Lys