Cruel but common. [ The Doctor could have easily left it there, but he continues on. ] There's always going to be some level of disparity. [ There had rarely been a world or time that he'd visited where there hadn't been some divide between the have's and the have not's. ]

I find it hard to believe that our memories are going to be preserved in some way if we leave. Anomalies like this usually result in people forgetting or only considering it a figment of some wild fever dream. Maybe you could try tattooing it on yourself.

[ It's a joke. Mostly. ]