I had to think through life events to remember when we started planning.
Married at 22/23 after grad school. bought used car to share, got apartment, got job, started 401k.
First, we had to pay off 30,000 student loans and save up for our house down payment. That took 2 years. Then we had to pay back parents for half the downpament. That took 1 year. (Still living like students, no new furniture to go with house, etc.)
Then we finished paying the mortgage off. That took 6 1/2 more years. At that point, our 401k and other savings may have totalled an unstable six figures with the market problems then, but we did buy some stocks on sale.
Then we really got started putting away 60% of our after tax income and 6 yrs. later we are 2/3s of the way to FI. (We still have the same garage sale furniture, 1380sf house, have 10 and 7 year old cars.) (I totalled our household gross income for those 15 years [from the SS statement] and while it was quite low to start and higher now, the average per year was just under 100k combined.)
So it should be another 2-3 years and we'll be where we want to be (thinking 1.2) somewhere between ages 40-42.