What comes on your mind first when you start to design a logo?

the connection between the logo, what it represents & who it targets

The logo must be matching between the content and colors and it must reflect the product indicate

It will depend on client and company.
First of all I will choose colour for the logo.

Objective, Message and target audience

Thanks for Answer.
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The first thing comes in mind is the message this logo is going to deliver.
It is very important to understand the message that logo has to spread.
This message contains the Mantra, Mission Statement and the services of that organization.
A logo should be comprehensive having all these messages in it.
There are many other things which should be considered while designing a logo, but I think those are out of the topic of this question.

Brand Positioning

shapes and colors.i know and feel, most of the time, just looking at the person how the logo will look like;i can see through the person and the logo just pops up.

About 50 different things come to mind.
Surprisingly, the design is way down the list.
I consider the brand/company's personality, the image or identity it wants to project, the people they are trying to reach, and a whole lot of other things.
A logo is one of (if not the) first form of communication a brand/company has about itself.
More often than not, it usually appears by itself, unaided by a headline, supporting visuals and other forms of communication that can make the viewer understand it better.
It has to be clear on what it wants to communicate.
Hence, should never be taken lightly.
Designing a logo is a lengthy process of fine-tuning.
I've never designed a logo where the client accepted it as is the first time.
It's hard as it should be.
But all the work is worth it.

my reaction and the reacting of the people about the thing that i will design...
after you imagine this moment you can create anything easily....

What is nature of business, first in my mind when I design logo, Because I select colors and logo style theme with nature of business, Hope this is answer