That's because the sole doesn't mould to your foot and to be honest I don't think the top moves much either, a bit maybe but nothing like they claim, i would say if their uncomfortable before you heat them then in my experiance theirs marginal improvement only my gripe is not with the shoes it's with the manufacturer who sell a shoe that's by it's very nature you won't know if it's any good until you have baked it in the oven then if it's still no good it's tough luck their not interested even if it does not do what they claim it will do plus is not an ongoing process every time you heat them they return to normal so you can't just keep on trying to alter them bit by bit until they are fitted once they cool that's that opportunity gone you have to start again