I was precocious/fortunate so I ran into ageism being “too young” to be something like a Lead a couple years ahead of my peers. In part because I worked in college, but more importantly because that team was so well run, and saw the wisdom in trying out some of my ideas to make things better. So I came out into the world both with programming experience and practical project management exposure.

“They” want very cookie cutter people. The more you try to control things, the fewer pleasant surprises you get.