Wow. This totally confuses me. So I see your watch running slower than mine, and your see mine running slower than yours. What time are they each showing upon my return?
You can't really learn much by asking such questions based on no clear understanding of the scenario or the basis on which arguments are being made. Understanding time dilation, differential ageing and SR (Special Relativity) require you to sit down and take the concepts one at a time: reference frames, the constancy of the speed of light, clock synchronisation, time dilation for a clock moving in some reference frame etc.Appreciate the clarification, though still confused. How do the two clocks in relative motion "know" they can never reunite?
Eventually, you can quite happily disentangle these apparent paradoxes, but you really need to begin at the beginning.