Why does it matter so much to atheists that God doesn't exist?

These are man made rules - made thousands of years ago for the use of the humans who lived thousands of years ago.

The people of the modern world have evolved past all of that nonsense.

Notice that I said their rules, not any gods rules.

What does "feeling like your life is over" mean and why is it not in any dictionary online?

A belief in a god is not the problem.

IT does not matter, mainly because it does not exist.

My problem is that people who try to shove their rules down everyone's throats - including by physical force - DO EXIST .

Why can’t the British eat or drink anything unless they place a table cloth on the table first?

And how do you deny hundreds of years of advancement in all fields of science?

Those rules that you are trying to reinstate are rules made by men who didn't know anything about the earth, nor anything about all of the other inhabitants of it. How can you not see that?

Because these are not any gods rules we are talking about.

How can I control my daily masturbating habit?

I do not personally care if you believe in a god or not.

THE BIBLE IS THE PROBLEM!

And then use and ENJOY these fantastic scientific advancements every single day of your life?

Why does my crush always looks at me in a sad way whenever I talk with other boys, and if he catch me staring on him then he go and flirt with other girls and then check if I am looking at him?

I am speaking to the US Bible thumpers here, of course ~ many of whom are flat-earthers who deny evolution and see scientists as evil people who are constantly trying, and succeeding, in disproving their beliefs one by one.