When I was growing up, there were a lot of lessons on staying safe online and data security, especially about using both a different password and a different username for each account. I still have most of my accounts under different services named differently! (And of course different passwords for everything too, hooray for password managers!)

If you happen to use different usernames for different things, how do you give them all names? Are they all themed about something you're interested in, are they just numbered (when I was in primary school, lots of people were lazy and had something like "alice1" "alice2"), or are they all just a random bunch of stuff with no order?