To illustrate this issue, I've constructed the below image that shows how Finland compares to Central Europe and Southern China (the areas I'm most interested in) in the Mercator projection and the Goode homolosine projection that accurately represents the relative areas of any two places on the earth. The difference is really quite striking:

I'm considering purchasing a poster with such an equal-area world map and hanging it on a wall somewhere I can see it every day. That way I could perhaps overcome the systematic error that the Mercator projection has taught me.