Do you remember all your password? Or, maybe do you use the same password on several services? I bet that the second option, which is unsafe, is more probable. I know that it is impossible to remember and generate very safe password for each service separably. Therefore, you need the tool which will allow you to store all your passwords securely.
Fortunately, there is the tool which will help you. Personally, I use it for several years. This tool is called KeePassX and the first version was released 10 years ago. The official version is available for Windows, Mac OS and Linux operating systems. However, there are also ways to use the same database file with all you password on your mobile device (Android or iOS) 🙂
The most important information is the fact, that KeePassX was Rewritten from scratch and 2.0 version which supports the new KeePass 2 (.kdbx) file format was released on December 7th 2015. Of course the tool not only stores your password, but it also will help you and generate for you very safe (i.e. random and complicated) new password. However, my favorite feature is the autofill functionality. You do not have to copy and paste the password (and login) any more 🙂
There is no official KeePassX tool version neither for Android nor for iOS. However, KeePassX uses KeePass format, so you can use any mobile application which supports this file format. For example, you can use MiniKeePass application on your iPhone, which is free. In case of Android device, you can use KeePassDroid program. Of course you need also something for synchronization, therefore you may use one of known cloud solutions for this purpose.
However, in order to keep the proper level of safety, you should encrypt your database file using password and key file. Of course, you should keep the key file safe, so do not upload this file into the cloud! You have to copy this file manually on all your devices.