There's "hell" in Hello and "good" in Goodbye. That's why you shouldn't be afraid of Goodbye but should be careful with the Hello, amirite?

but you don't get a goodbye unless you say a hello.
take a chance. if you make a mistake, you have an opportunity to learn and grow from it. take it and run with it

There's a town in Texas that tried to legalize saying "Heaveno" as the town's standard greeting, because "Hello" is too negative. I'm not sure if it worked, though...