My 2p worth.
If you have a well paid job, but still harbour dreams of becoming a pilot, why not use your job as a secure jumping off point and have a crack?
Life isn't all about money. That is something it has taken me until my late twenties to realise.
The partners at the firm I work for earn well in excess of half a million pounds a year, some earn seven figure sums. I've noticed many of them don't seem that happy, as they sell their souls to their jobs. They earn fortunes but buy into a lifestyle that costs a fortune to maintain. A lifestyle that takes its toll after a while. Many are functioning alcoholics, wage slaves with absent kids at boarding school (£20k per year, per child), massive overheads and wives who are probably screwing the personal trainer/tennis coach.
There is a lot to be said for getting a decent backup career going first. It sounds like you're well on the way with that. As you say mortgaging you parents' property would hvae been a terrible option. But now that you're earning, if you have no responsibilities and can afford the training, why not give it a shot?
You're a long time dead.