That's normal according to the books Mike.
The training books that I have read indicate it is normal for train
for 5-10 mins and then stop because the dog will loose interest!
It's so true. Buddy and I train no longer then that each day.
He's so excited to start but you can see him loose interest about
6 -7 mins later

He even walks away from treats!
However, he does remember what we did from one day to the next