professors must understand his/her students

I just want to share this feeling with you guys. :| I just can't move on with this, first thing in school our professor's must understand us right? Last Friday March 18, 2011 is the deadline of our project in one of our major subject, I was in a hurray that day because I need to finalized the projects and review if there is some error that will occur, after I reviewed it of-course I saved it and go to school just to pass it but then I forgot to save the videos that I used in the project, our home is 28KM away to my school and I can't simply go back to our home because I came to school is almost 4pm and the deadline is 5pm. I go to faculty room and I tried to convince my professor that, if it is okay that I should pass our project on Saturday March 19, 2011 because I forgot to bring the CD where I already burn our project and unfortunately in the flask this I forgot to save the videos that I used in the project but it seems that our prof is not believing in me, our prof didn't understand how I felt that day, it seems that the reasons that I've told to my prof is a lie. so sad :(