If you say that a situation is not a bed of roses or is no bed of roses, you mean that it is not all pleasant, and that there are some bad parts too. Life for the Prime Minister has not been a bed of roses. He had looked forward to this job, though he had known it would be no bed of roses. Prison life is certainly no bed of roses. Note: You can also say that a situation is not all roses. His time with the transport union was not all roses. Note: The bed referred to here is a flower bed.