How many grumpy developers do you know? 

Some developers continually ask questions in an attempt to understand what's required and to identify what could go wrong.  Others seem to ask fewer questions, and don't appear to be as preoccupied with exceptions. 

The perception is that one 'type' of developer is constantly placing barriers in the way of progress, whereas the other is very positive.  Of course each 'type' wants to do the best job they can.  What's interesting is the perception that their approach has on the people they are speaking with.

Is the difference down to early training?  Is it difficult for developers that were initially trained to use a waterfall based approach not to think in a certain way.  Whereas those that have only ever used agile approaches are more excepting to move forward into the unknown.

Of course it's also likely that those developers that were originally trained to use waterfall based methodologies are older than those that have always used agile.  So it could simply be down to age...