It is almost impossible to survive in a cloud based technology such as ours without having:
- Mastered SSH and SSH ssh Keys
- Installing a password manager such as LastPass or devising some other strategy for managing usernames and passwords. (I've been using LastPass, usually multiple times a day, since at least 2012. So far it has worked well for me, and has done a great job of protecting my privacy and keeping my actions on the Internet secure.)
Using the same username and password everywhere, or relying on your memory are not sustainable strategies. Regardless of what you read, in most cases LastPass or similar tools provide the safest and most reliable solution.