I think this video is very interesting. The first thing you may question when someone tells you the earth may be flat is, well what about planes and flights? What about all the "shortcuts" you can take since "of course" the earth is a globe?
Well watch this video. It's pretty short.
Amazingly dumb video
For starters, just a basic understanding of logistics will inform that it's more cost effective for airlines to have few main connecting hubs in order to centralize all the expensive infrastructure to operate. FedEx does the same with his packages... they all go through Memphis even though it don't seem like a logical route. It's cost efficient.
As for the "flat map" it's simply a different projection the the usual mercator we are used to. The one showed has the very inconvenient problem of making the south pole a thin ring that seem to edge the "flat earth".
Antartica of course has been explored and mapped in details and its no where close to be a thin layer...
Sigh.