Some FAA inspectors have a 90% failure rate the first time for a CFI. I had one of those inspectors and I did not pass the oral marking my first failed checkride. Felt like crap but I learned a lot and it only made me better the next time around. Some say age can be a factor in the inspectors decisions. I'm 19 so that probably didn't help much because when I went home and talked to my instructor he told me that some of his other CFI students whose ages were in the 40's weren't drilled as hard. It still wasn't easy for them but I have to believe that their age was a factor. I'm not blaming age on my own failure because I just plain didn't do a good enough job to meet the PTS.