Being unable to get approved for a loan, and if you are approved there are higher rates and more restrictions.
You would have trouble getting an apartment, because usually they check your credit score before allowing you to rent the place (especially on a lease) and therefore finding a place to live would be hard.
Trouble getting a job, especially at a place like a bank. You must have good credit in order to get a job like that.
Normally bad credit can also mean higher insurance premiums, and troubles with getting anything that has to do with a contract (like a phone).