livegolf
I would say there is no magical or secret recipe but some if the factors you mention might come into play.
What is the definition of early? I know folks who retired at 50 , they werent rich but they cashed in their house, moved to a small town and are happg and comfortable. One of my good friends is the opposite, has several million dollars , no need to work , is 63 but he keeps going. Hes been with his company 37 years.
People generally over estimate what they need for retirement. Of course longeavity, spending habits , debt levels , health etc all play a part in how much you neec.
the three best pieces of advice I would give a young person are:
1. begin saving early . Start putting money away in your teens from summer jobs etc, let that money compound and grow.
2. Pay yourself first. Related to #1 . Put 5/10/15/20 % every paycheck away. Automatic withdrawal so you never see it.
3. Live modestly , within your means and only buy what you need not want. The last is/was the hard part for me.
Both my kids now 16 and 18 started have already amassed nice little bank accounts and my daughter invested in her first mutual fund. School ,curriculum here doesn't teach personal finance , we need to educate kids better in that regard.