I have heard concrete take 100 years to fully cure. The cream is worn away over time naturally and you can see exposed limestone, depending on type of concrete, when it is gone. If the concrete is broom finished then the cream is the top part which has the broom stroke imprint in it. New concrete is most vulnerable.
Thanks for the help Danny, good to see that someone is actually willing to help the little guy. We all gotta start somewhere and I highly doubt even the most experienced person here came into this business knowing everything. Don't have time to call right now so I shot you an email.