The Mr Am and I went for my first "after injury" ride yesterday.
I rode my beloved GT (most would say "its too old buy a new bike")
Its a full suspension ("why do you ride that here, its too much bike for these trails")
I rode the Henry Hudson ("you call that a trail? thought you were a mountain biker")
I wore my work clothes as I didnt have time to change ("call yourself a cyclist? You wore dress slacks and a cotton shirt?")
My socks did not match my outfit ("ugh")
I wore my brand new downhill gloves because I didnt have a chance to wear them yet and wanted to see how they felt ("really?")
But I dont give one hoot what I looked like or what anyone thought about how I dressed, or what I rode. I was purely happy I was able to ride again.
As for the shoulder, after half an hour it started to ache. It will take some time to get that area back in shape. And yes, a month off the bike does set you back just a tiny bit, even without an injury to recover from.