Gratitude is the driving force of the Grand Overall Design, and expressing it with a compliment makes others aware of the gratitude you express. It costs nothing, maybe a few seconds, and leaves others feeling better. Some people are so accomplished and steady in their convictions that they don't need others' compliments, and some even have a hard time receiving them gracefully. But that can be overcome, and if people express it often enough, you will start to believe it, and then the real magic starts to happen!
That is because positivity and negativity are both ever widening spirals, and once you get on the positive one, you can quickly start soaring on the updraft of positive energy. But keep your cool, and ground yourself. This will allow you better vision of where you are going, and keep your aim true...