Absence makes the heart grow fonder, love is wise, love knows no age... Is there anything about love that is consistent? That isn't contrary, that isn't a generality? I asked the wisest individuals I know in their 20s, 40s, 60s and 90s who are in successful relationships to discern more clearly what love is. Here are their responses to the questions:

How do you define love?
Why is love important?
What is the key to making love last?

Brittany (23 years old, in a relationship of almost four years):

1. "Love is safe, consistent, always good and pure. It is putting the other first when they can do nothing in return or for you in return. Love is the wanting of the highest good for one another, even if it takes yourself out of the equation."

2. "We need love because true love transforms lives. It heals and free us to be the truest versions of ourselves. We need love because when we are in the presence of true love we reach a point of self-actualization, where we are known, understood and appreciated for all we are. There is nothing in us we hide, we are fully known".

3. "The key to making love last is dedication to the love and to your partner. The couples that pose the commitment to be for each other forever are the couples that grow together through the seasons that are meant to pull them apart. True love never gives up. It never leaves. True love stays when it makes the most sense to go. It is healthy, hard and given as much as it is received. Love works when the partners are committed to each other. Whatever life crushing problem you face is not exclusively your problem: it becomes 'our' hurdle to tackle. And you will, together, because you are committed."

Marni and Greg (48 and 50 years old, in a marriage of 22 years):

1. "Love is trust and high expectations for integrity. It is fun and it is hard work. It is a bond both physical and spiritual. It transcends everything else in life and it gets stronger as time moves on."

2. "Love is important because it allows for tolerance. It allows people to be imperfect. It allows for forgiveness. It allows for understanding. Above all other emotions, it gets you through the tough times in life."

3. "Love lasts because of communication first and foremost. It also lasts because of respect and because each person is willing to forgive and put the other person's needs on par with their own."

Tom Dean (72 years old, previously married for 13 years)

1. "Love is in the words of others:

'Love is patient and kind; it is not jealous, conceited or proud. Love is not ill-mannered or selfish or irritable. Love does not keep a record of wrongs; love is not happy with evil, but happy with the truth. Love never gives up, and its faith, hope and patience never fail. Love is eternal.' -1 Corinthians 13:4-8"

2. "Love is important and lasts due to:

Reconciliation: Although any relationship that has lasted for a goodly number of years has had many rocky and rough patches, there is a reconciliation of past mistakes and a forgiveness of prior sins by both parties. Bygones are bygones, and what is more important is working together to keep what has survived intact.

Determination: To keep things on track and running as smoothly as possible in spite of day to day vicissitudes, irritabilities and diurnal impositions. Each party is willing and even happy to provide some 'comfort zone' of daily forgiveness and latitude for petty and minor habits, etc. of the other person. Living together is far more preferable than living apart.

Recognition: At this stage of life, each party recognizes that there are going to be inevitable health issues, both physical and mental, that may emerge or are already evident. There is a willingness and even a desire to assist, aid, abet and provide succor and substance in times of significant (or even minor) duress of the body.

Finalization: The cognizance that life is waning, and may end at any moment, yet making the most of every day, and not dwelling on what may happen, but on what can be done to enjoy life to the fullest in every manner possible. And that occurs only by sharing the joyous, happy, uplifting and equally as important, the mundane, painful, unpleasant and unpredictable aspects of life. Whatever life brings, sharing it with the one you love makes it all worth the time, effort and energy expended."

Norm Dean (92 years old, in a marriage of 45 years):

1. "Love is a feeling of togetherness and a desire to share many kinds of experiences. Love is wanting the best for the other person under most all circumstances."

2. "Love is important because without it, a relationship is empty and almost meaningless. It’s hard to put into words, but [my wife] and I describe each other as soul mates."

3. "The key for a lasting love is knowing how the other person feels and thinks, responding accordingly, and being considerate in every way."

My own opinion:

1. Love is being unequivocally understood; to see the best of yourself reflected in the way the other person respects, celebrates and cherishes you.

2. Love is the most important thing I know because it sustains you and makes you humble. With love we learn to respect ourselves more, but foremost to know another person so entirely that their joys, triumphs, sorrows and defeats become our own.

3. The key to making love last is understanding when you have failed (something that is hard to do) and striking a balance between knowing what is best for you as well as your partner. But regardless of their circumstances, you will hold their heart with priority because love sometimes requires sacrifice.

Thank you to Dane, whose love is the greatest gift I have ever been given.