loosing or quitting ?

Interesting topic... and a very complex one from what I've experienced...

Some dogs with good nose just can't seem to "figure it out" due to whatever(dry conditions/high wind/too much scent, etc.)...

Some quit it because they're just sorry and don't want to have to work for it...

Some quit because they physically can't go anymore, regardless if they can or want to...

Some are just smart enough to quit because they've learned which times you will come to help them and which times you won't...(what I personally prefer)

... and I'm sure there are just as many shades inbetween...