mktsoi wrote:...every time when i travel between Schengen countries. they still check my passport like i need a visa.
Did you want to say "when you are flying between Schengen-countries"?
In this case the airline will establish your identity on departure. On arrival there is no further check at all, you can leave the airport - and that's it.
You will not see any immigration-officers, not on departure, not on arrival.
I know folks who live in Belgium, 500 meters away from the (land)border to Germany.
They cross every day, from home to work and back, sometimes additionally for shopping or simply for a walk out in the green.
You will have a hard time trying to be checked at the crossing, as there is simply no guard to be seen anywhere. The border there is mainly forests and lawns, you will find some stones marking the border.
This is of course the same for all Schengen-land-borders.
If you are lucky you can show your passport to a grazing cow. I don't know if it would be very interested though...
It's like crossing from co. Tipperary to co. Limerick.
Here, the UK and RoI don't even trust each other... The "CTA"-agreement, already practically doesn't exist anymore. This ensures lenghty checks everyone will have to endure when coming back from practically anywhere. Or why not enjoy the soon-to-be introduced checks between Ireland and "the North", when going for a tea just 2 k's away with the grandma on the "other" side...
Oh - and as paranoid politicians seem to be unable to think clearly, try flying from Dublin to Cork (or the other way). This should be clearly domestic.
On arrival you will find that you have to pass... immigration
because there is simply no separate channel for domestic flights.