Mikeliv88:
I don't really see your point. One of my best friends did his PhD after roughly 10years out in Computational Fluid Simulation (or something similar weird ;-) and he's a professor now. I was out of my (social science) subject for many years, and I am pretty confident (I know, don't praise the day before the night). Further, I agree with TreeOfLife; you're not the only returner in the world.
I would consider these few thoughts:
1) Check with the programme itself and go through the class descriptions. Do you think you can take on it?
2) You probably didn't sleep the last 4 years, but gained knowledge in other areas, wheresoever. Include that, don't make it a waste. It's an asset.
3) Being out connects you to the real world, meaning: your motivation is different. You are older, you know what working means, you know how important it is to bring money home and to stay focused. Another asset, and useful, too.
Best, Sebastian.