It's not something easily defined, it's different for everybody and you never stop looking because you are constantly evolving and your perceptions change and grow.............i've been 'searching' since i was about 14, i even did a philosophy degree to try and further my understanding...........(what a waste of time .....lol)
I've come to the conclusion though that so called 'searching' is fruitless......Harmony IS when you don't have to struggle for it.......it's looking at a duckpond in the sunlight and smiling to yourself as the ducks squabble...........lol.........
Basically, be aware of your heart, don't fixate on, and sweat the small stuff and go with the flow..............
but everyone is different......it took some serious life experiences to get me to let go of the future and stop sweating the past........