Note: in order to save the battery life, the screen automatically turns off after 3 seconds. Press the button to turn it back on. If you have an Octopus Watch Motion Edition, tap the touch screen button.
When a reminder pops up, the screen will automatically turn on for 3 seconds.
To understand the difference between a reminder and an event, read this post: https://joyfamilytech.freshdesk.com/en/support/solutions/articles/23000005135-what-is-the-difference-between-an-event-and-a-reminder-