Refining some wording in unittest partial mock doc

Some of the descriptions were addressed in first person, but have now been changed to address the user reading the documentation instead.

Author: KarnbirKhera

Doc/library/unittest.mock-examples.rst

@@ -600,12 +600,12 @@ this list of calls for us::
 Partial mocking
 ~~~~~~~~~~~~~~~
 
-In some tests I wanted to mock out a call to :meth:`datetime.date.today`
-to return a known date, but I didn't want to prevent the code under test from
+For some tests you may want to mock out a call to :meth:`datetime.date.today`
+to return a known date, but you may not want to prevent the code under test from
 creating new date objects. Unfortunately :class:`datetime.date` is written in C, and
-so I couldn't just monkey-patch out the static :meth:`datetime.date.today` method.
+so you cannot just monkey-patch out the static :meth:`datetime.date.today` method.
 
-I found a simple way of doing this that involved effectively wrapping the date
+A simple way of doing this involves effectively wrapping the date
 class with a mock, but passing through calls to the constructor to the real
 class (and returning real instances).