Great points! The problem with any “investment” for the future is that it requires sacrificing some pleasure in the present. Your idea of doing things on purpose is so helpful.
Here’s a tip for enjoying now without torpedoing your future: pick hobbies that have up front costs, but not continued ones. For example, once you own climbing gear, using it to go climbing on most cliffs is free. Same with a musical instrument-a guitar might cost a grand, but you don’t have to pay to be able to play it. Golf, skiing, and SCUBA on the other hand? Better save that until after your loans are paid.