A number of years ago, Jane Goodall wrote a book titled A Reason to Hope, which was truly inspirational.
I was fortunate to be speaking at an event where she spoke too, and we got to know each other a little.
With the understanding she shares through her work with wild chimps and other apes, she really does give us all a reason to hope.
The fact that hope springs eternal has kept many a lonely person from jumping off a bridge.
In our bleakest moments, we can have the hope that someone or something is just around the corner for us.
There is always a reason to hang on and stick around, but sometimes what you are hoping for may not be good for you.
Sometimes you need to look at whether what you are hoping for is actually helping or hurting you, so you can make the decision to change, if you should.
For example, if you have a crush on someone and that person has shown no interest, hoping against hope that she or he will come around is unhealthy.
Once someone has said that you are not the one, the only choice you have is to move on.
If you don’t, you will only succeed in pushing the other person further away.
You can find love and a relationship, but you can’t find it with someone if he or she has turned you down.
And if you keep trying, you will lose some self-esteem every time you hear the word no.
You have to learn to let go, so you can find the right person for you, and this is never as easy as it sounds.
Feelings linger.
If you have had a few dozen or more hours of conversation and connection with someone, he or she may have taken up a little space in your heart, and now getting that space back can be emotionally challenging and painful.
But holding on to something that will never happen is even more painful and will slow you down in other areas of your life.
You have to realise that you are not letting go of hope but letting go of your own unhealthy fantasy.
Once you make that realisation and understand that there is someone or something that will fill your desire, then you are on the road to reality - and then you can make your dreams come true.
Spending your life a-wishin’ and a-hopin’ and never getting what you wish for can be lonely and may end up depressing you.
Look, I wanted to be a rock star and it didn’t happen, but all that energy I put into it performing and songwriting has made me a better speaker and writer.
Had I not changed my path - when I realised I would never be Mick Jagger - I could have ended up chasing that dream and missing the fulfilling work I am now doing.
It is hard to let go of a dream, but if it isn’t going to happen and trying to reach it is hurting you, it’s time to find another goal.
Remember that happiness comes from moving toward what you want.
So find something else or find someone else who will return the energy you are wanting to share.
You won’t get what you’re looking for unless you look.

- Dr Barton Goldsmith, a psychotherapist in Westlake Village, California, is the author of The Happy Couple: How to Make Happiness a Habit One Little Loving Thing at a Time. Follow his daily insights on Twitter at @BartonGoldsmith, or e-mail him at Barton@bartongoldsmith.com