As I understand it, the faster I accelerate myself the slower time for
me moves as compared to an observer I left behind. Andromeda my be 2
million light years away but at higher and higher speeds accelerated to
I could get there in no time at all, but it would still be two million
years for the observer I left on earth. I also understand that if you
travel in a strait line eventually you will come back to where you
started. So given that, I could accelerate myself to some minute
fraction under the speed of light then coast and return to the place I
left in a few seconds. To the observer I left behind billions and
billions of years may have past making the universe to him that much
older but to me the universe would only be a few seconds older. How can
the universe be two different ages when I arrive back? Does
decelerating myself to the original speed I started at cause time to
speed up that much? Am I actually accelerating myself again to get back
to the speed of the original observer?

I know I may be making what you all may consider stupid mistakes, but I
am just an amateur trying to understand relativity a bit better. Any
answers would be greatly appreciated.

-Al