Your circumstances, whether real or imagined, should not impede you from making progress. Your mind is the primary vehicle to move you forward in any project, and even if the craftsman loses all of his tools, his brain can still function. He can think about complicated problems that he needs to solve when he does get his tools back. This is making your time as alive as possible. When you are stuck on a train for an hour a day, you could let that time die and do nothing because you say the circumstance doesn’t allow for anything else—but your mind works. Your brain can still process information, reflect, observe, and make progress. There are no excuses for lost time.