Because he's the only Saiyan in his world - they're a superhuman race of people, basically - and he thinks someone is going to take it over or destroy it if he isn't around.
There's a looot of empty space up there... but there's also big balls of fire called stars, black holes that can eat everything, and moons!
"I'm assuming something like that's happened to him before, hence the caution...jeez, like something outta one of my Japanese animes..."
Yeah- that's what we're trying not to think about.
People want me dead.
Out in the forest.
And one of them might be Jack The Ripper. And whoever that particular one is, is definitely an oracle.
According to my sources at least.
Sometimes it is, could've been a killer or a bear. Or both.
1.5 imperial gallons of tea were consumed during the writing of this post

(gives a wave back)
Um - we're doing fine. How are you?
(this girl looks like she just got done with a workout herself - albeit of the weights kind)