What does it mean when a lawyer says there is a conflict of interest? Why do I have to show ID and retain a lawyer before getting my questions answered ?
To protect the public from uneducated advice, only lawyers are allowed to provide legal advice. Lawyers are vetted and licensed by their State or Provincial Law Societies. Usually, lawyers have undergraduate degrees before they complete their law degree and then eg in BC they must also complete a year-long practicum training including three months of further classroom practice preparation training.
Lawyers are "Called to the Bar" and accepted by the Court as Solicitors = as "Officers of the Court" before they are an advocate for any client, thus they have multiple rules of ethics as well as regulations and other laws they must follow.
When you become a client of a lawyer, you are always a client of that lawyer meaning a lawyer cannot act against their client forever without express permission. Thus a "conflict of interest" check must be completed before anyone can become a client of a lawyer. The names of the proposed new client and all the opposing parties in the dispute have to be checked to confirm the lawyer is not being asked to act against a former client even if the lawyer has had no contact with the old client for decades.