You need to make that clear in the op.
Not every old Asian guy in pictures is Lao Tzu or Confucius. In fact, both Lao Tzu and Confucius are traditionally depicted in scholarly robes. This guy is wearing peasant clothing and exposing his bare chest.
And I'm grandma Moses.
His grandmother did.
She's a tricky one, I wouldn't rule her out yet.
I dont think there is one secret to happiness, thankfully, there are many ways to find it.
Although if there was....maybe it would be to realise it is always fleeting, but always comes back.
Twinkies(Hostess, not the other kinds)
Secret: End the desire for ever lasting happiness.
Helping someone. Working on something creative. Meeting new people and slowly learning to love many friends.
Yes, by accepting that which you can't change, you change your perception of it, gaining you inner peace ant through it happiness.
By accepting it, and dealing with it, you can then move on, no matter is it was a loss, moving on will bring you that inner peace. I've been there, believe me, it's the only way to have any happiness in the future.