John,
Other than the other's comments, I think what you heard applies to views not to cursors, for when you do a select * in a view, and then change the structure of the base table(s), then the view definition is now incomplete and you get an error.
"The five senses obstruct or deform the apprehension of reality."
Jorge L. Borges?
"Premature optimization is the root of all evil in programming."
Donald Knuth, repeating C. A. R. Hoare
"To die for a religion is easier than to live it absolutely"
Jorge L. Borges