You only have a finite amount of time and energy and to excel in any field a lot is required.
Should you spread your focus there are two outcomes:
1. You don't give each area enough time and energy.
2. You lose balance in other areas of life.
It's almost like you're putting on a bed sheet that's too small... to get one corner over the mattress another one pops off.
The number of hours needed (the sheet) won't stretch over the hours you have available (the mattress) and something has to give.
Until you determine where your focus should lie, you may have to spread yourself thin and spend more time and energy than you'd like.
That's okay, it's a necessary process.
Should you find something that provides you with true fulfillment...
Narrow your focus and run with it.