As a novice Linux user, I didn't know I had to add a line into /etc/fstab for automatic mount upon boot. It took me some minutes to research and notice the right process (at first, I even entered s3fs#mybucket into the command line).
This change will (hopefully) save time to unseasoned users.
received "should not have others permissions" when mounting
did chmod 640 and received "should not have group permissions"
used chmod 600 after creating the password file and had no problems