Oh, it’s not nearly as neat as yours, I’m afraid. :} Pinkpeony73 was my username for Club Penguin — which was an online multiplayer game, just in case you’re not familiar with it. CP is gone now, but ever since then “Pinkpeony” or “Peony” has been my username for pretty much everything. XD Plus, peonies are one of my favorite flowers. Pink ones, especially.
The numbers are just kinda “special family numbers,” IDK if there’s any significance behind them. They’ve been around for as long as I can remember. X]
I remember Club Penguin; never got into it myself, but I remember seeing ads for it. Hey, if it’s something you like, that’s all that really matters. I’ve had a few different usernames over the years, most of which I’ve dropped for one reason or another. At least you’re not likely to change your liking for flowers.