actually it just happen naturally.
what is a lucky number? its a number that brings luck to you? or you personally experience something lucky which related with that number, or simply because of that particular numbers follows you or appear in your sight or related with anything about you in your life. So of course indirectly you will fall in love with that numbers.
another reason would be the financial value, the intangible value which recognize by the society.

Its just a natural habit, human being tends to avoid anything which related with something they fear with. Such like the number of 4 for chinese, it is natural for human being to fear of dead, so indirectly we, the human will try to avoid them.

yea just like 13 is a bad number in some countries 

for chinese ,yes it is 

I think so. Its autosuggestion, aka self fulfilling prophecy. Try this bowling alley experiment. Keep saying to yourself, "sei lor" when you throw the ball. You might find it landing in the gutter most of the time. Now try to play another game and tell yourself "strike" when you throw the ball. Quite likely you won't do as bad. If you got money and time, you can repeat the experiment 10-20 times and see the results for yourself.

What the number sounds like in your language can make all the difference. To cancel out the effects in any language, simple. Just don't believe in it.