The reason why certain countries look bigger or smaller than others is that of something called the Mercator Projection. Putting a 3D planet on a two-dimensional world map was something of a challenge for early cartographers, and so a Flemish geographer and cartographer named Gerardus Mercator came up with a solution for the most accurate world map. In 1569 he designed an atlas that could be accurately used for navigation purposes, but the downside was that his system distorted the size of objects depending on their position relative to the equator. Because of this, landmasses like Antarctica and Greenland appeared much bigger than they actually are. Though there are around 40 types of map projections, from conical to polyhedral and retroazimuthal depicting the true size maps, this one is still used the most because of its convenience and simplicity. And none of these projections can be titled 'the real world map,' just because they all depict the same Earth through a different lens.
To show how incorrect our understanding of countries by size is, a website called thetruesize.com lets you move landmasses into different locations. Bored Panda has played a bit on world maps with countries, provided by this site, and this is what we found.
#4 Australia Is Way Bigger Than You May Think - It Covers Almost The Whole Of Europe
#6 Indonesia Would Spread Almost Across The Whole Of Russia
#7 Greenland Is Not So Big When Compared To USA And Brazil
#9 California Moved Onto The UK Shows They're Quite Similar In Size