Fact is we don't know. As you pointed out, the sun has been around for a very long time. Our known history isn't much more than a fraction of a fraction in geological time. We do know that the sun's radiation can be deadly without protection and that is the current dilemma. Our magnetic shield is in a weakened state and the sun is growing angry. What does that mean? Who knows. I, for one, see protective shields down and increased solar activity as somewhat concerning. It is better to be aware of the possibilities than to be ignorant of what is possible.