With the sheer number of hacks and attacks out there it is very likely at some point one of your accounts has been compromised somewhere. This constant threat makes it imperative that we use multiple passwords across the web. We can't trust the company we are using to not mess up somewhere and loose control of our account login. If you are sharing your passwords between your bank and some random car forum then you are a prime target. Security experts all say you should never reuse passwords and that they should be super long with crazy characters like, )(*:LKUIkjasdfijui*(&U3. If you are like me and can't remember what you had for lunch yesterday and have hundreds of passwords to remember then those security experts are smoking something.
However, there are ways to meet the security experts expectations. The easiest way I have found is with one master password to control all the other passwords at a site called LastPass. LastPass will install on your phone and computer with no issues and ensure you have access to all your passwords at any time. The people at LastPass know what they are doing with ensuring all your passwords are safe, by not knowing your master password they can never compromise your passwords. In fact if you forget your master password it's all over for you and the only option they have is to delete your account and start over. They are capable of auditing all your accounts and informing you when one of them has been compromised and recommending you change your password. There are other solutions Keepass, 1password and a few others. I don't know them all and I don't have experience with them but LastPass I have done the research on and use daily and trust them to have the encryption right.