Locke- book 2- chapter 12- page 108-111- "complex ideas"

In Lockes chapter of complex ideas, he says that complex ideas are just simple ideas compounded together. Just like 1+1=2. Locke says complex ideas can all be divided into groups of modes, substances and relations. Locke says complex ideas of modes are dependent on the simpler idea. They are dependent on the simpler idea either from variations of the simple idea or a compound of simple ideas to make up a complex idea. Locke say complex ideas of substances are a combination of things that are of a simple idea to make a complex idea like dull , or hardness. The third he says is relations which is comparing one idea to another. Locke makes a crazy point at the end of this section stating that if we were to trace what our minds have done throughout or whole life, it is extraordinary. It combines, senses, erases, imagines, simle ideas to complex, it changes its feeling on things. The mind just does such miraculous things that I think so many people take for granted. What would you do if you couldn't make ideas or think for that matter, you would be an invalid.