It's human nature to hold on to things for the sake of holding on to them; for fear of there not being a replacement if we let it go. We have a habit of gripping tight the hot potato because we are scared there won't be another one!
How many people are stuck in stressful jobs for example? Jobs that are contributing to the detriment of their health; just because they are frightened of there not being another job; especially when there are so many financial outgoings to cover? The same can be said of the outgrown relationship because the fear is of being alone.
Imagine the incredible weight off the shoulders when we let this outgrown burden go. Life is not so bad after all; in fact there is a glimmer of hope because its possible to see the wood for the trees; despite the fear of never finding another job; or never meeting someone special again.
The mind can become clearer once that initial panic subsides. Humans have a tremendous ability to adapt and go with the flow once a decision has been made. So no matter what the R-Complex demands in those days or weeks after relinquishing the dreaded job, or the outgrown relationship; life is going to get better in the long run. There are, however, the rare exceptions where the decision is the wrong choice and life goes from bad to worse. That is a sad fact of life ...
The breathing space experienced after the burden release should be quite inspiring when combined with a positive mental attitude. For someone who has been left seriously depressed due to the work pressures, the feeling of negative isn't going to leave them immediately. It may take a while - weeks or months - but once the subconscious becomes aware that the cause of the stress, and the unhappiness, is no longer around; there should be a good recovery.
Having a welcomed rest from the negative surroundings, and negative situation, should have a beneficial effect within a week or two. New, and fresh, opportunities should be greeted with optimism. Adding an exciting new dimension to life. For new opportunities will arrive, and the chance for fresh new beginnings will be there for the taking.