That happens, then you need to figure out how to handle them. Sometimes when you show them what they really need 'the light goes on' and they don't care about what they asked for anymore (or worse someone else shows it to them and they don't buy from you at all despite your customer focus). Other times they remain convinced they need that thing and so you need to gike it to them lest they buy from someone else).

this it a hard problem to figure out, good luck.