We are trying now. I am 31 and my husband is 32. We've been married 10 years. We aren't financially independent but we're in a great place, rapidly paying off debt. :-)
I was absolutely baby crazy when I was 24. We were living across the country from everyone we knew, my husband was having a horrible time in graduate school (basically his graduate advisor was sucking him dry), we had no real money (but we had no real debt either), and no idea what the future looked like but I wanted a baby so badly. My husband talked me out of it, and I am very grateful.
Because we haven't had kids, we were able to experiment with our careers and our living situations without a huge amount of stress. I spent a year teaching sewing and learning every craft I ever wanted while working at a craft studio. I also started gardening more and I now know more about growing vegetables in Texas than anyone I know. I fixed up an 80 year old house and sold it. My husband taught high school for 2 years, something he always wanted to try, then decided to go back to graduate school and had an amazing time, did awesome research, got published and presented at conferences and eventually landed an awesome job as a space engineer. Between the teaching and the second graduate school, I found out what it is like to be financially insecure. We were living off my meager sewing-instructor paycheck. I sold our bed and sofa to pay our mortgage payment one month. I learned a lot about minimalism and what really matters in life. I learned our marriage can survive a lot. When my husband went back to school, I decided I wanted a more secure career, too, and went back to get my nursing degree. I no longer worry about my husband losing his job as I have one of the most diverse and employable degrees on the job market.
If we get pregnant soon, I will have two years experience as an acute care nurse and will be able to work PRN and make 2x as much as I do per hour, and work as many or as few days as I want. We live by my parents who are both retiring this year and are excited to be active grandparents. My husband will have 2 1/2 years at his job and will most likely be in a more senior position. He has great benefits.
If we don't get pregnant by 35 (I have PCOS, so this is always a possibility and not terribly unlikely, but so far everything looks good), I will hike the Appalachian trail, we will take a bicycle tour of Europe, we'll continue our current careers/passions/frugality and maybe we'll adopt children.
As for energy levels, I am more active now than I was at 24. But I'm also more comfortable with the realities of what life is all about. I worry less, enjoy life more, and I think those are really invaluable things I will bring into motherhood.