It is easy to be enthusiastic when you start something new. Everyone has fresh legs at the beginning of the race. Everyone is excited for the honeymoon. Everyone can have beginners luck. This is that instant gratification when you start something new. There is always more energy, more excitement because the newness.
It is something you’ve never done before so your knowledge and skill is expanding at a rapid rate. The learning curve is giant and exponential. You can go from complete beginner to mediocre pretty darn fast. Eventually the repetition and familiarity hit. The learning slows down. What used to be new and exciting is now normal. You begin to where down and it becomes boring. This is where champions are made.
The challenge is keeping the same enthusiasm and energy you had at the beginning until the very end. If you are fresh and energized when everyone else is tired or quits then you will have the advantage.