Sometimes life is deceptive. For example, we look at happy people and after talking with them for a while we realize that they are also very grateful people. The gratitude seeps into their conversation not in a scripted way, but naturally as if it bubbles out of them whether they want it to or not. So we go away thinking they are happy because they have so much to be grateful for. That is the illusion!
If you talk longer or get to know these people more you realize they are not grateful because they are happy, they are happy because they are grateful. The secret to happiness and love is gratitude. Gratitude is also the secret to Living in Truth. When we are looking for those Golden Goods and rejoice in them, and give thanks for them, we are happy and filled with love.
In short, happiness does not ensure gratitude, but gratitude always ensures happiness.