Why using do/does/did ?

[sh.hazeri]

What is diffrence between :

I searched ....
I did search ....

[euncu]

***neither a teacher nor a native-speaker***

The second suggests that the effort you put in for the search was much more than the first one.

or the second would be used as an answer to such a question:

Q: Do you really want me to believe that you searched ?
A: I did search...What makes it too hard for you to believe?

But a native-speaker will give you more satisfactory reply, so I suggest you to wait for a while.

[sh.hazeri]

From a native speaker point of view ?