It's true time goes fast. Everyone feels that in some capacity or another. For me, the best remedy for the quickness of time's passing is to be constantly planting...that way you are also harvesting. In other words, I am not nostalgic for my 20's and have absolutely no issue with being a 31 year old and I think much of that contentment can be attributed towards using those years wisely and investing in us and our future.
I didn't do those years perfectly, and I'm sure I'm not doing these ones just right either, but I do have something to show for them and that is critical. Whether that investment was time spent working towards a more satisfying career path, or the investment was saving money to give yourself more options, or traveling the world and exposing yourself to places you may never have had the opportunity to see.... You've fulfilled the goal. Your years have not been in vein. There's something, whether tangible or inherent, to show for them.
Some days I get incredibly frustrated and I feel too stagnant, but I'm not. Chances are you're not either. Planting can be slow. It can be tedious. It will test your patience and that's something hard to battle with day in and day out. But it is worth it. and we're doing it. In some form or another, we have more options, we have more experience, we have more understanding.... But it's up to us. The years go fast and time doesn't wait until you're ready.