...is the remedy for tiredness and exhaustion after an effort of some kind, such as hard physical or mental labour, or the long struggle against illness.
Olive can be usefully contrasted with Hornbeam, which is the remedy for tiredness felt before an effort has been made.
The remedy gives us what we need to restore our strength and the faith we need to continue an effort. We may feel energised; or we may at last be able to rest properly.
Dr Bach's description
Those who have suffered much mentally or physically and are so exhausted and weary that they feel they have no more strength to make any effort. Daily life is hard work for them, without pleasure.
- The Twelve Healers and Other Remedies
Quoted from http://www.bachcentre.com