[O] How to get rid of first line indent?

[Birnle]

Dear group,

How do I get rid of the (first) line indent in org mode? I type some 
text (book length) in:

* Some heading text
Here is some text in one line in
visual mode that wraps nicely
and looks like it should.

** Another header
And some more text in just one
line in visual mode that wraps
as it should.

Then I do something – I don’t know what it is, but suddenly the 
first line of the same text is indented to the level of the header by 
white space:

* Some heading text
  Here is some text in one line
in visual mode that wraps nicely
and looks like it should.

** Another header
   And some more text in just
one line in visual mode that
wraps as it should.

I’ve searched for hours but couldn’t find a solution. As a totally 
new Emacs and org (and evil) mode user I don’t know what to do. Please 
help!

Best,
Birnle