What you are describing is a very common experience and, arguably, never goes away. I have done a series of gigs over the last six montns with some top drawer players; John Etheridege, Jim Mullen, Julian Siegel, Tony Kofi etc etc. I recorded most of the gigs on my Zoom H1 and have had the opportunity to listen back to most of them and what is interesting is the fact that, whilst recognising a personal style (something that all jazz musicians aspire to), a lot of that comes from repetition of phrases and lines driven by muscle memory rather than the creative process. On the few occasions when it comes together, it is usually because I am mentally in a space when I can be focussed on the music itself rather than the 'occasion' and can both remember everything I have ever learned and forget it all at the same time. It is a zen-like thing. YOu practice to internalise stuff not to 'learn' it and, eventually, if you are lucky, it comes out in your playing. FOr me, it happens at most once or twice a gig and, ig I am lucky, I have one or two gigs a year where I can do no wrong.
I was once thrilled to learn that Dizzy Gillespie felt that his 'hit rate' was about the same!!
THe subject is covered comprehensively in Barry Green's 'Inner Game of Music' (£6 for kindle or, on Amazon Marketplace, for the hard copy)
http://www.amazon.co.uk/Inner-Game-Music-Timothy-Gallwey/dp/0330300172/ref=sr_1_1?s=books&ie=UTF8&qid=1386839049&sr=1-1&keywords=barry+green+the+inner+game+of+music