I'm doing this little thing where I do 10 push ups every day. To make a game of it, I am allowed to miss no more than one day and I have the option of making up missed days as well. I could even do 10 push ups at 11:55 pm, then do 10 at 12:01 am and not have to do a set for almost 48 more hours, but that requires staying up late.
I've missed a day here and there. Not sure exactly how many but at least one per week. So let's call 26 out of 31 an 84% or a B on the old grading scale. I will state the obvious: the push ups are easier the more frequently I do them. In fact, skipping a day now and again seems to actually help. My long term goal is to get to the point where I just do some push ups every morning without thinking about it and if I miss a day, no big deal.