You can start very young and unfunded and still get there.
You can start older and better funded and still get there, this is often practical... get a degree in something useful, use that to get a decent job, use that to fund flight training. Hint: you can take out a loan against your own 401k after you build it up (read your employer's fine print though).
Or take the advice of the Village People:
https://youtu.be/nmGuy0jievs?t=30