Even the most noble of the sacrifices is based on "self satisfaction". Jesus Christ himself was crucified for the sake of his people for "self satisfaction". That's why you shouldn't expect anything in return when you help someone. Because the moment you expect something, your act would become worthless.
It doesn't matter what you achieve in life. It's how you live that really matters. Countless men have lost their lives in war without fulfilling their life's ambitions. Shiba stood by his convictions, no matter how lonely he got. So I think that in the end, he must've been happier than anyone.
Then I ask you, what do you define as the beginning of the sky? At one hundred meter or even one thousand meters, it isn't much different from right here. The sole difference is the air density and water concentration. So, this is where sky begins. Anything above the earth belongs to the domain of sky.