Work day.. EPIC FAIL

Today when i woke up, I was extremely positive that I was going to pass this  'test day' at what was going to be my new job. I go in, at 4:00pm get introduced filled some kind of paper work, then got right to it. did whatever they wanted me to do. So, I had cleaner and a towel, also a broom and dust pan in my had all day. The moment someone got up to leave, i was there, to clean up. as well as got to know some of the co workers and joke around whenever it was necessary, usually when someone else started it. over all, i had a very good day. There was many people that had said i was doing a very good job. and i got along with everyone i worked with today. So at the end of the day, i was feeling very confident that i finally had a job! The manager that was to determine whether or not I had a job, he had nothing but nice things to say about me. he said I did an amazing job, I was very enthusiastic, very friendly, Worked very hard. My confidence growing even more. I sit there listening to the praises and even thank him for such.. The the BUT comes... "We do not feel that this is the place for you. you showed excellent work today, and if today was like a normal busy day we would have been able to see more of what potential you have,  but since its was a slack type of day, and were not able to show what you can preform at a faster speed, we do not want to hire you here right now, and be too overwhelmed with the work"  I think i literally felt my world come crashing down. I hardly ever cry at something like this, but i was LOOKING FORWARD to this job. all the while, he keeps apologizing, i wonder what is he not telling me? what horrible job did i really do? what did i do wrong? what could i have done better? all the while crying my eyes out, trying to make him change his mind, "But i can do it, how can you tell me i cant do the super busy days if you don't want to put me through that test? I dont understand. I really dont. So once again, i have no job. I have to keep looking..... Will I ever find one?