300k net worth at 30 would be pretty awesome.
Ironically, that was one of my exact goals that I set for myself back in college. There was a lot of number crunching that went into that goal, and it seemed like a meaningful hurdle.
Lately, I have made more of a series of 5-year financial plans. These are based on where I want to be in a variety of financial aspects (house, net worth, investments, etc) five years out, with a sequence of one-year strategies to get there.
Early on, if you focus on how much you can put away it will serve you well. For the first many years of my career, I put 15% to 401k plus the 8% company match. The 15-year note on a modest townhome also helped.
The bottom line is that the focus was primarily on how much I could save versus my means. It may have been demoralizing to compare to the population in general or conversely may have led to complacency.