You may need to sacrifice something or someone
In doing something you love, sometimes you need to give up another passion or leave some people in your life to fulfill it. It could make you sad to choose one over the other just because the first weighs heavier.
It may not last a lifetime
Your energy may not be strong enough to do it while you’re still alive. You could also find or learn another thing and suddenly choose to that instead. Change is constant and it’s either a dangerous thing or for the better.
You could die for it
Like literally die doing it. Sometimes, what you dreamed of doing for the rest of your life may take your life as well. People may sometimes overdo these purposes and passions that they forget to take care of themselves. Please still have time to rest and relax, or else, your life could be shorter than planned by the universe.