When I do I-search: or I-search-backward , it starts right away from the first word it find.

word
wor[cursor]d ;<= I press `ctrl+r` word [enter] cursor moves to previous
word

For example, when I am in I-search, I want to start doing backward search and press ctrl+r but in the first press it remains in the current found word (cursor move into its beginning) and on the second press to ctrl+r, `emacs jumps to the found word on backward.

=> I was wondering when the switch from I-search: to I-search-backward or visa versa, can the action take place on the first click instead of two?

When I do I-search: or I-search-backward , it starts right away from the first word it find.

Original behavior:

word1                                           |[cursor]word1 ; cursor moves here 
wor[cursor]d2 ;<= I press `ctrl+r` word [enter] |word2
word3                                           |word3

For example, when I am in I-search, I want to start doing backward search and press ctrl+r but in the first press it remains in the current found word (cursor move into its beginning) and on the second press to ctrl+r, `emacs jumps to the found word on backward.

Example:

word1                                           |word1
wor[cursor]d2 ;<= I press `ctrl+s` word [enter] |word2
word3                                           |word3[cursor]; cursor moves here

then

word1                                           |word1
word2                                           |word2
word3[cursor] ;<= I press `ctrl+r` word [enter] |[cursor]word3 ; cursor moves here                                          

at this stage I want cursor to move beginning of word2 like it should do on its original behavior.

=> I was wondering when the switch from I-search: to I-search-backward or visa versa, can the action take place on the first click instead of two?