Because we are used to thinking something is good/bad, we assume it that way, mostly there is no reason in it, just because of our thoughts.
It is hard to convey my word, but I tried to make a conversation for it.
John: Hey Marie, why don't you test Sushi?
Marie: It tastes terrible.
John: You just think that way. You haven't even tried it once. I think you just .................. to yourself.
Could you help me find a statement that means this way? Or could you please tell me your own sentence here?
I think you've just convinced yourself that it's horrible.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.