Luke 8:13 But the ones on the rock are those who, when they hear, receive the word with joy; and these have no root, who believe for a while and in time of temptation fall away.
How many good ideas have you had in your life where you had every intention of starting something only to find the idea was put aside and forgotten?
Just because we come up with the ideas does not make us the people God would have us to be; He wants us to carry out those ideas and not just to think about them.
When God says He wants us to do something it is not just a happy thought to get us through the next day or week. He wants us to set time aside and move forward with the task He has given us.