I always communicate to my Tai Chi students the importance of regular practice. However, there is a more important quality - the ability to go regularly beyond your comfort zone.
The first time you step outside your comfort zone can be a daunting thing. It does not have to be physical. You might have to address a large group of people, or operate a new kind of computer program, or start a new job. Whatever challenges you might face, moving out of your comfort zone on a regular basis makes you grow at a fantastic rate. You also learn to relax more, because your comfort zone will be extended beyond it's previous capacity.
So going back to Bruce Lee's filming. Not only was he traveling abroad to film, but he was also prepared to leave his familiar clothes and family behind. Comfort was the furthest thing from his mind. Self-improvement was his priority.
So go on...... push yourself.