Human, being a complicated life form, things without and things within are literally being complicated too. Human heart is well-protected, it resides in the core of life, from within vitality is channeled. Though, we see or perhaps feel that the hearts around us are far more protected than we could imagine. It is to the extent that humans feel reluctant to reach out from inside, forever keeping their truest self from the light. While not expressing the true form of heart, humans adapt to the elements of environment and reshape themselves accordingly to what is perceived as the most fit. The bond that forms in such manner may only last for that long, a predictable "long". To be the most fit definitely has its price to pay, the energy. One day, tiredness will find its way to the front door of your heart's chamber to claim the debt that you have owed to yourself. You need a rest, re-energize yourself ONLY after you have let go of the bond that binds.
Show what you have to show, be our true self and that may guarantee an eternal bond of heart, bond that is not established nor maintained one-sidedly. It is as simple as key and lock concept, compatibility is the key and lock is the compatibility, there is no forcing through the hard way.
When thing goes naturally as what it is meant to be, it looks the most beautiful.