编辑下面这篇短文，使其更具流畅性和可读性。输出编辑后的短文。



When I was young I always wanted to be a astronaut. I was fascinated by the mysteries of space and the possibility of exploring other planets. However, as I grew older, I realized that becoming an astronaut was not an easy task. It required me to have excellent grades in math and science, as well as physical fitness.
When I was young, my childhood dream was to become an astronaut. I was captivated by the enigma of space and the prospect of discovering new planets. But as time went on, I came to the realization that achieving this goal was no easy feat. It demanded top-notch abilities in math and science, in addition to robust physical fitness.