Long isn't really a good word to describe the voyage. Tedious is a little bit closer to the mark. It's hard to explain to someone who hasn't done it. You think about ten years on Earth and it's not really that long. It's only about an eighth of your life. A blink in the timeline of humanity. You can look back on ten years of your life and wonder at how swiftly it passed. But that's only because you were living a life. When you're on a spaceship, life feels as far away as home.
There were things to do, but not really enough. The novelty of space travel wore off pretty quick. The ship was small, and each "day" (which could only be measured as an interval of exactly 24 hours) trickled by in an indistinguishable blur of precisely prescribed monotony. There were exercises, simulations, data charts to read, but time only seemed to pass quickly in sleep.
I emerged from that journey a different person. One isn't supposed to have that much time to think. I felt very old afterward, even though it was really everyone else who had grown old. Because of time dilation, everyone I had known was dead.
I tried to put all that behind me, though, as I stepped out onto the earth of a new world. The air tasted different. The gravity was very slightly higher. The planet felt very alien. It was a different world. But I was a different person, and it was time to start my new life.