How do you define true happiness? Sleep, gratitude, and mindfulness?

When it comes to happiness, I think loving someone is a very important criterion for happiness. From this point of view, this article's definition of happiness is not enough for me. I expect more than these three factors such as how to find out who is a lifetime lover or fiance something.

Let's suppose that I am totally happy with sleep, gratitude, and mindfulness. But will I be happy when I am the only person who lives well by myself in this all-couple-world or all-family-world? Will the loneliness hurt other contentments about sleep, gratitude, and mindfulness? 

Loving someone is a kind of all-day-long mental connection like a blood vessel between two people. Although in the daytime I work in a very different and distant workplace and I cannot see the lover, I feel my lover exists, and 'love particles' like red blood cell exchanges simultaneously and unsightly through the blood vessel between two loving people.

Love provides me with a mental bottom line or safety feeling. Loving is a sun in a dark area such as other bad feelings from human relationships or career problems. For these reasons, I think love should be added to the Secrets to Happiness.