Although it's common for individuals to have hobbies, the autistic is more likely than others to have a very intense or hyper-focused interest. For example, one ASD individual may read voraciously while another one may sing to karaoke non-stop.
One of the surprising realities is that the intense interest may lie within an area of notable impairment. We tend to assume that the person who reads seven books a week has good reading comprehension. Similarly, it would be understandable to believe that the autistic who writes fictional narratives in notebooks piled high and spilling over the desk is a good storyteller.
I often see that the autistic is fixated and fascinated with information that he cannot decipher or use in a meaningful way. For example, one gentleman was fascinated with words. He printed his favorite words on 3 x 5 cards, which he then taped to the wall in parallel columns. The surprising fact was that he didn't know what the words meant. Instead, he appreciated some features of their letter or sound combinations. He was also very attuned to patterns of syllables and symmetry (e.g., he loved 3-syllable words and palindromes).
Another individual on the spectrum as fascinated with math. She gravitated toward liking specific symbols and equations. Odd and prime numbers felt very meaningful to her and mental calculations were as easy as pie. However, she struggled to use numbers for useful, day-to-day tasks (e.g., budgeting, calculating elapsed time, or measuring the area of a room).
It feels reasonable and satisfying to encourage someone to pursue what interests them ( e.g., "Do what you love, and you'll never work a day in your life"). However, the reality can be that interest and ability level do not always go hand-in-hand. This contrast may be even starker in the autism spectrum, where interests can be intense and ability levels uneven.
Preferences are relevant, but should not be the only factor considered when planning an occupation or career path.