I find that sometimes I have to drag myself out of the house to get on the bike. I think my problem is knowing there will be a lot of traffic to deal with. To often I actually talk myself out of riding all together (it's to cold, it's cloudy, to windy etc etc). Poor excuses to say the least. Once I am actually on the road and pedaling I find I LOVE it and by the time I get back I'm thinking what a great time I had. Now that I have found a couple of friends to ride with, that makes it all the more exciting to ride. I have even set challenges for myself (getting better at going downhill).
There are some days though that I KNOW I have to rest. Sometimes instead of riding I may walk my dog in Mission Trails or my husband and I will go do some hiking. Forcing yourself to ride everyday is NEVER good, I think it defeats the purpose of having fun. Take a break now and then and don't feel guilty, it does no good.