For many people, the sense of "this will only happen once, never to be repeated" is what they love about live performance. For me, the same thing is true in the studio. If it's not fresh in the studio, there's no way it will withstand the test of repeated listenings as a recording. You have to stay present, over and over, take after take, delivering the absolute best, liveliest performance you can. And that, to me, is every bit as challenging and exciting as a live performance. Just me and the microphone. And then, when the work is done, it's preserved forever, to be enjoyed over and over. I LOVE that.
Of course, there is no audience in the studio, no sense of love and reciprocity, no implied challenge of winning them over, no applause. So live performance does have some powerful and unique aspects that the studio can't deliver. I can dig that..
But, as in many areas of my life, I can get tired of doing the same thing on a routine basis. Performing in a long run of a play, or singing the same songs night after night... sometimes boredom starts to edge in. I know how to look for the ways of keeping a performance fresh and alive over the long haul (heck, I sang Psycho Killer over a thousand times, and rarely did it ever get stale for me.) But I tend to itch, yearning to move on. In the same vein, I've never been able to stay in a job for long. It's how I'm built.
Being in front of a microphone and exploring the moment and knowing that whatever I do will be captured is an ultimate high for me. And...when the work is done, I get to move on to something new. That's nice!