Chinese Characters- Look and Compare

http://www.chinessimo.net/ Look and compare: 人入, 大太, 天夫, 木本..... Why are these ideograms so alike? Is there a reason to draw an extra point or a longer stroke so the head extends to the side or not ? Two characters, instead of one !! An ebook for the curious and those who want to learn ! http://payhip.com/b/r8H4