I started birding in 2016, both a really good and bad time to begin this journey.
eBird was well-established, so finding birds is easier than ever. As a 28 year-old, I was just starting to earn money to travel.
On the flip side, populations are declining, my spouse, while interested in the outdoors, does not bird, and I've got an almost 2 year-old with another on the way.
At 526, I've got no final number in mind. I'm hoping that I'm still able to head to Colombia in a few months, which should get me around 700.
My immediate goals are hitting 400 in Texas (at 399 since January!) and getting another 37 to hit 500 in the ABA. The latter will take some time since I don't foresee much significant travel in the next couple of years.
I think international travel may become more doable afterward, and even if I'm seeing common birds or sneaking away for a day on a family trip perhaps I could hit 1000 worldwide by the end of the decade, or soon thereafter. I guess that is the goal I will set for now. 1000 by 2030!
Honestly, seeing about 10% of all birds during my lifetime is not a goal I would have foreseen when I started this hobby and realized there were over 10,000 species out there. 1500+ would be a birding life well lived.