While this is true, everything is not cast in stone, people are changing positions and opportunities are rising. The org structure in most places is dynamic, additionally leaders usually happy to delegate their responsibilities.
The growth into managerial roles happens kind of naturally, take more responsibility - become a team lead, take even more responsibility become some sort of manager. It has less to do with knowledge or diplomas more with the desire to take responsibility to be a leader and take responsibility for the others. The only limit here is the amount of responsibility you can handle.
Appreciate the personal response!
Imagine you are walking through the woods, not 100% sure where you are going, but you turn left, then somebody told you always turn right in the woods (for some reason) and you did, then you got a new idea that you need to go backwards that will help you for some reason... at the end of the day you end up lost without a clue where to go. so you are sitting there in the dark asking how do I restart this level....well... there is no restart button, you are where you are... in the woods... probably alone.
What is also true at the same time - the sun will rise tomorrow, and it will be a new day to try out an find your own way. And it will help a lot to use the experience of the previous day - remembering what you saw, where you took the turn, who you met .... always learning , always moving forward. With this mindset we are never lost in our journey.
In other words, to start over we just need to learn and keep going. Have a great journey!