A person believes something (or should) because they have examined the available evidence and either they believe the evidence or they do not believe the evidence.
Belief is really not a choice, at a trial do you chose to believe the person is guilty. It is not like going to a car lot to buy a car and you chose the car of your choice (because you like it , price,etc..).
Like your moon made of cheese, well that is kind of a far out there example. But one that is built more around reality is. Do you believe man went to the moon. I for one did in younger years, but after examining the evidence from the Bible and other areas, I now no longer believe man went to the moon. So i did not chose to stop believing that men went to the moon, but i did stop believing that men went to the moon, because i now no long believe the evidence that they did.
That is kind of what the parable of the soils is saying, about the second soil. Something came along to cause this soil to doubt at one time what they believed in. In this day and age that something could be science and their lies about creation or another religion or a sinful life choice. But like the parable, i do not believe these people just out of the blue chose one day just to not believe.
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.
But he who received the seed on stony places, this is he who hears the word and immediately receives it with joy; yet he has no root in himself, but endures only for a while. For when tribulation or persecution arises because of the word, immediately he stumbles.
These likewise are the ones sown on stony ground who, when they hear the word, immediately receive it with gladness; and they have no root in themselves, and so endure only for a time. Afterward, when tribulation or persecution arises for the word’s sake, immediately they stumble.