Thanks for the replies.

@Sagrid I think I prefer not to tweak the settings for the time being.

@thedicemaster which setting option would I find the long-press back option?

On my Nexus 4 phone, I can hold the back button and a pop up menu appeared with "show full history" and "exit," running verion 25 of Opera. I'm running the same verion on my LG G3, yet it doesn't provide the same menu. Is there a way to turn on the menu?

TIA.