Perhaps it's worth mentioning here that with most aviation authorities you can qualify for an Instrument Rating and never have actually flown in cloud.
Flying in "real" conditions where you are flying in and out of cloud with cloud at different levels with different orientations with respect to the true horizon can be far more disorienting than flying with the screens up whilst under training.
Throw in some rain and turbulence or even wind shear with fatigue in the mix and you have more ingredients for undesired consequences.