Why did my phone have a pass code when I didn't put one now I'm completely locked out

[AC Question]

Front screen is locked and I can't use my phone Galaxy 4s mini

 

[GRIMWALD]

Perhaps one of the following methods will be of help.
Google find my phone is probably the best way but a factory rest may be more convenient.

7 Ways to Bypass Android's Secured Lock Screen « Android Gadget Hacks

GRIM