How do you remember your passwords ?

When you buy a new laptop or tablet, you will have the job of setting up all your online accounts, and to do that you will need your usernames and passwords. It becomes a problem if, for example, you forget the password to your email account and your old device is no longer working or your email address is linked to an old service provider you no longer use. It is therefore important that you have all your passwords stored somewhere safe, either in a paper notebook (in a safe place), or in a special app that stores them with one master password that gives you access to them all. Of course it is better if you can just remember them all, but most people can't do that unless they are all the same which is not a good idea. 
I recommend something called two-device verification. It allows you to get back into your device or account if you get locked out, and it also alerts you if your account is being hacked into. It is common to have a laptop or tablet as the main device and a mobile phone as the secondary device. But the main thing is that you prepare ahead of time and think about how to make your devices and accounts secure yet always accessible to you.
This is something that Threave Tech Support can help you with.