I like this description by @firstname.lastname@example.org of the difference between “dabblers” and “S-tier” people (who are the absolute best at something):
There is an infinite list of exciting things to learn, but the Dabbler knows they have finite time, so they dabble. They get 80% of the juice, and they move on. Respect.
S-Tier knows the last 10% of the challenge is the hardest, but it also teaches you the most.