Come by

come by (to acquire, to gain, to get, to win) - uzyskać, zdobyć, dojść do czegoś.
come by (to be gained, to be acquired, to be won) - zostać zdobytym, zostać osiągniętym.
come by (visit) - wpaść do kogoś, zajrzeć.

1. How did he ever come by so much money. [...gain so much...]
2. The wisdom is one of the hardest things to come by. [...hardest things to acquire]
3. Order doesn't come by itself. [is not acquired] /Mandelbrot/
4. Well, a lot of successes come by mistake. [are won because of mistake]
5. A top result is hard to come by. [...hard to gain]
6. The feeling of satisfaction comes by overcoming something. [is got by overcoming...]
7. You must come by and talk us [visit and talk]