Discovery Helps Delivery
A fundamental reason for starting the encounter Do phase with Discovery is that it will help me to optimise the delivery of any arguments or presentations that I intend to give. It may even deter me from giving them at all.
If, for example, I discover that my client is reeling from the consequences of a company reorganisation, then I will probably defer the presentation of ideas about our long-term relationship until a better time. While it may be disappointing to shelve work that I have taken a lot of trouble to prepare, it could be better to do this, rather than irritate or confuse my client with something that has become inappropriate.