Andrés, I can relate exactly to what you say! I also started studying late in life (at 44) and I am so fortunate to have found my teacher, who is a world class professional. It makes a big difference to study with somone who has performed in major opera companies in the world, to impart the life experience of being under the direction of different conductors - people have also taught my teacher. In addition to academic achievement, she has had the experience of learning from other singers, also, and at one time went to a teacher who was a physician/pianist who specialized in the larynx. All of these many "real world" influences teach more than just an academic classroom could teach.
Your analogy of learning to fly a plane is excellent. The best teacher is one who has lots of personal experience as well as the knowledge.

It may be time for me to compile the threads on singing that I have traced. We have had a number of discussions where I posted links to websites on warming up, vocal health, etc.

As André advised, don't push your voice into a range that is not its best natural range. Just because I can hit some low notes does not mean I should sing there- it puts stress on my vocal cords. I resist when people ask me to sing a particular sea shanty that they like to sing along. Whenever I lead it, I always have to be careful not to stress my voice and I sing something right after in my real range (or go to the ladies room and do some vocal exercises to 'get my voice back').

Alice Flynn