The other candle is external. Figuratively, we hold it in our hands to help us make our way through life. We can follow its light, and others can see its light, too. It is very helpful. But as much as we try to protect it, it is vulnerable to being snuffed out by the tides and storms of life's "weather", by accidents, and by assaults from others. When that candle is extinguished, and it will be from time to time, because that's how life is, you can lose your way. You might lose your happiness, your joy, and your laughter. Your world will seem very dark. If don't re-kindle it, you can think that you have lost your "self". But you have not.
It glows in your heart. It comes from your fundamental goodness and your essence, from the permanent essential traits and abilities that are yours forever. It comes from your willingness to take the risks of being kind, being forgiving, looking for the good in others, being flexible, being grateful, and allowing yourself guilt-free pleasures in life. It may seem odd, but it also is easier to find and understand when you open yourself up to true mirthful laughter and humor. You don't have be become a comedian or "be" funny. You do have to let yourself "see" funny.
And, as it happens, it is much easier to find if you are willing to believe that you deserve happiness. Although that inner candle is always there in all of us, those who do not believe they deserve happiness, or who aren't willing to master the attitudes that bring happiness, have a much harder time finding their inner candle.