unable to define local function because it has the same name as the file

How is this error even possible, seriously ?

I got the following error: unable to define local function 'myfname' because it has the same name as the file

And here is what the console is showing me:

Error: File: myfname.m Line: 4 Column: 15 Function with duplicate name "myfname" cannot be defined.

Seriously what is happening here ?