I've heard it said that composing is a jealous muse. For me, I suspect this is true. To put myself in the mode that composes, I find I have to isolate myself mentally and physically. It's as if whatever it is inside me that can compose will only cooperate when it's convinced that I'm committed to it and it alone. This is a solitary creative process, but being in the Helfman group was an effective counterweight.
It's invaluable to have much more experienced composers commenting on a work in progress. After spending so much time in composing isolation, I can easily get attached to something that doesn't quite work, and having this pointed out by a knowing group of people who have your best interests in mind - a great piece - is a safety net that actually frees me to be more daring in those quiet one-on-one moments with myself.