A while ago I finally grasped that things don't control my emotions. I do.
I have also realized that while this is a beautiful concept, putting it into practice is very difficult indeed. It requires the same nurturing that a marriage or a rose garden (how's that for inappropriate equivalencies!) do.
For example, I have a hard time being exposed to conflict. It makes me extremely uncomfortable, likely for those family reasons mentioned in your quote.
On the other hand, I once took a date to a restaurant and saw a mouse dart under our table. She didn't see it and I didn't flinch. Yay me. lol