It's a simple yes or no question, right? Either you can choose what you believe in the same way you can choose what to have for breakfast, or you can't in the same way you can't choose to obey the law of gravity.
Well, no. Whether or not something is a choice is not a simple binary yes or no. It is, as nearly everything else is, a continuum. We don't normally notice it, because we usually only encounter examples at extreme ends of the continuum, like breakfast or gravity.
But there are examples of in-betweens. Consider a person with OCD. Does such a person choose to wash their hands over and over? To a degree, they do, but to a degree they don't.
It's the same with choosing what to believe. You form beliefs based on what you see and hear, and you can't really change that. But you can choose what to look at and who to listen to. And even when beliefs are deliberately chosen, it still takes a long time to really convince yourself of it.