Jonnyb42

I have thought about it and I have found to be confused about something, regarding the twin paradox. As I know it, the twin paradox (set up to emphasize my confusion) is as follows: Two spaceships floating in space pointing away from each other, lets say A and B. When B accelerates and approaches the speed of light (as observed by A), B's time is slowed down, and when B returns to A, B is younger than A.
My confusion is, if we make the "observer" to be B, then it is A that is approaching the speed of light, and when the two meet again, A should be younger than B. Why when analyzing the same scenario and just changing which ship is the observer changes which ship has gone further into time?