When the discovery process is iterative, there is never a point at which you have an estimate for the whole task. Each new discovery step may be the last one or

When the discovery process is iterative, there is never a point at which you have an estimate for the whole task. Each new discovery step may be the last one or it might lead to more steps, and you won't know until you complete some step, look for the next one, and realize the project is done. A knowledgeable developer can predict how this cycle goes and explain that an estimate of the whole task is impossible, and they will be quite literally and completely correct in that case.