The top five reasons why cyclocross is the fastest growing sport in America (says me, that's who):
5. What else are you going to do in November and December?
4. It never lasts more than an hour no matter how slow you go.
3. Mud is better than road rash. Added benefit: shaving is not necessary because legs are usually covered with either lycra or mud.
2. You're going to need to get a bike specifically made for 'cross. That old mountain bike in the shed weighs a ton and you wouldn't want to ruin your nice road bike in the mud. If romantically involved, cyclocross may be the excuse you need to indulge your bike addiction: "I know I can't get to the lawnmower with all the bikes, but honey, I just need this one more bike for 'cross."
1. You're going to need a B bike too because what's the point of even trying to race with only one bike. Stuff breaks and gets clogged with mud. If you have a mechanical and no back up bike in the pits, you DNF and lose your entry fee. DNF 20 times in your career and that's enough wasted entry fees to buy a decent pit bike for free. Don't wait any longer. Hopefully you didn't need the "just this one more bike" thing above to get your first 'cross bike approved by your significant other.