Life of Buddha, to be taken seriously?
the Buddha taught that there is unsatisfactoriness in this world and the way out of it which is more systemised as the 4 Noble Truths.

If these stories help you understand unsatisfactoriness and help you come out of it or inspire you in any way to practice and strengthen your faith, by all means use them. If not leave them aside without outright rejection and concentrate on what appeals to you.

What is most important is you follow the Noble 8 Fold Path divided into the 3 Fold Training which results in understanding the 4 Noble Truths.