do i have to be happy?

today i sent five applications. five is quite good for a single day, i think. i feel satisfied. don't ask me to whom, because i suffer from the tendency to forget it (there was a medical foundation, a research institute about Mediterranean area, three regional agencies).
the technique is: read the website of the institution you are interested in, check if you can apply on line and do that, if there is no application on line find out the information you need and write the motivation letter to be sent with the CV.
i wonder: if they answer you that they do not have any chance to recrute you now, but you have a nice CV and then it will be inserted in their databases, in case in the future they have a vacancy, do i have to be happy or not? maybe yes, because the alternative is that they don't anwer at all.
:)