Why is it that you can tell someone something, and they don't remember it the next minute?
Stony ground, deaf ears, hard hearts, cares of the world, and Satan who steals away the word. Jesus explained this particular situation in Mark Chapter Four...the parable of the sower.
Yesterday, I preached a funeral for a 59 year old man. As I preached, I could see some faces that were receiving the word of the Lord. I could also see some "stony" looking faces, and some looks of disdain. It sure is a discouraging task, at times, to sow the seeds of God, and to see hardly any results.
One person in particular hardly remembers what you preached..the word was snatched away by the enemy.
However, it's worth all the labor of sowing if just one person's life is changed.
Keep on sowing...your labor is not in vain, and you will reap a harvest after awhile.