Is it possible for a human to live happily forever alone?

Yes. I've just given a tech update to my students that deals with traveling at 'warp speeds', which is the only way humans would be able to form an intergalactic alliance. Sadly, it looks like this will never happen.

Even terraforming Mars is a very long shot and is uneccesary.

We'll max out at around 10 billion pepole and we have plenty of resources and energy for all to have a clean, sustainable world.

But the most important thing needed is 'to live happily ever after' we have to focus on our spiritual growth.

Basically, this means that:

1) We treat others as we'd like to be treated.

2) We use our talents to make the world a better place.

3) If you believe in God, thank Him for all that you have and ask him to assist you in creating the best world possible.

Why should I let my dad back into my life?

This question does not provide enough details to enable me give an unbiased answer.

What could have happened if Hitler had died before 1933 (for example during WWI)?

This is a hypothetical that would be impossible to discern. Something would have happened with the post-WW1 Tensions. Germany was stuck with ridiculous demands after WW1 ended. Making the Germans the responsible party bankrupted the nation and regardless if Nazism rose up in Germany tensions would have still been

Is Boise, Idaho the future biggest tech-city in USA?

I think it's on the short list. Besides having Micron and and HP campuses, here, the area's been attracting tech startups with its lifestyle and growth. A new mass transit plan has been approved that includes better service to the community, a light rail system, GreenBike kiosks, and automated cars, and educators,