Young ‘Āisha (May Allah be pleased with her) lived with the Prophet (May peace and blessings be upon him) in Medina.
Medina was a city in the desert.
One day the Prophet (May peace and blessings be upon him) went on a trip.
Young ‘Āisha and some other Muslims went with him.
On the way back they stopped to rest for a while.
When they started traveling again they forgot someone.
They forgot young ‘Āisha.
Young ‘Āisha had lost her necklace.
She was busy looking for it when the Muslims left.
The Muslims did not know they had left young ‘Āisha behind.
She was all alone in the big desert.
Young ‘Āisha (May Allah be pleased with her) did not cry.
She was not worried.
She sat down where she was and waited for the Muslims to realize she was not with them.
She knew they would come back to the last place they saw her.
Eventually young ‘Āisha (May Allah be pleased with her) went to sleep.
While she was sleep another Muslim came.
He was checking to see if the Muslims had left any of their belongings behind.
Young ‘Āisha (May Allah be pleased with her) was not a bag or anyone’s luggage but she did get left behind.
The Muslim saw young ‘Āisha (May Allah be pleased with her) sleeping and said:
إِنَّا لله و إنَّا إِلَيْهِ رَاجِعُوْن
That means: ”We belong to Allah and we will return to Him.”
Young ‘Āisha (May Allah be pleased with her) woke up and the Muslim helped her get back to the Prophet (May peace and blessings be upon him) and the rest of the Muslims.
Lessons:
Do not waste.
If you are lost stay where you are so that people can find you.
When something bad happens we say: إِنَّا لله و إنَّا إِلَيْهِ رَاجِغُوْن “We belong to Allah and we will return to Him.”
 

References:
Ṣaḥīḥ al-Bukhāri 2:593-594
‘Umdah al-Qāri 13:333
Faṭḥ al-Bāri 10:387, 386, 416