Theme: Travel, and leaving home

When Vincent was young, he erases his name from the wall where his father measured his height; displaying his wish to leave "home" permanently. It's also a forshadowing of Vincent no longer identifying himself as Vincent, but as Jerome.

Vincent discloses that he wishes to leave the Earth, his home.
“Maybe it’s just my growing dislike for this one[Earth].” – Jerome (voice over)

Vincent leaves his home one night, never to return to his home. He ripped a picture of himself from the family photo and puts it in his shirt pocket. This is another example of his wish to "disappear" from the "home", ie Earth, that wasn't so kind to him.

He “moved around a lot.”

"I never saved anything for the swimback!" - Jerome
This is similiar to the one way trip to Titan. He only has about 30 years to live, one way trip is all that is required. One way trip to the other side of the shore, and one way trip to Titan.

And Jerome travels to the space, knowing that he might not live to come back home.

When Jerome asked Eugene, “Where are you going?” he replied, “I’m traveling too.” Eugene is traveling to place where his "legs wouldn’t matter", and knowing he achieved his dream on Earth. (see Dream)