Last Saturday was my first time on a bike in about 10 years. It was also my first time on a road bike since I was probably 9 or 10 years old (I'm 38 now).
I have got to say that I have thoroughly enjoyed it. I can't wait for the next day's ride. I am planning on commuting to work 4 days a week on the bike, which is just over 9 miles each way.
I did my longest ride so far tonight. It was a 8 mile ride with 460' of climbing. I averaged 16.9 MPH. I was pretty excited with that result and am planning on doing the ride to work at least once next week, probably Wednesday.
That's an incredible average speed for your first ride and with that amount of climbing is very impressive. 9 miles each way is not a trivial distance, so just make sure you don't over do it at first (once you're used to it, it will be a breeze).
I'll definitely be careful not to overdue it in the early going. This next week I'll only ride to work once and will take it easy on the way in so that I can push it on the way home.
In fairness to how much I've been enjoying biking, we've had beautiful weather here the last week, but that will be changing soon. I live 45 minutes outside Vancouver, BC, so we typically get a lot of rain! That will certainly make things a bit more challenging, but I'm not going to let it stop me.