Hi Simple Gifts. As you say everyone is different and there is no rhyme nor reason to it. I was an instructor/ lecturer and spoke all day everyday. Going through the radiation treatment about week six into it, I started to get the tiredness and the effects began. Dry mouth, sores and blotchy skin and I couldn't talk very long as my tomgue became swollen. I had a tongue disection and reconstruction plus a bunch of other stuff though, which it sounds like you are not. So listening to my fellow radiation companions you may just sail right through it from a talking point of view. The tiredness will come and go, you'll feel like a million bucks today and like you've been stampeeded the next. Don't push it or you will become sicker and the colds and germs will realy love you then. In truth I have not worked a full day or earned a wage since my surgery in 2006 almost a year it was supposed to be an eighteen week recovery. I work from home whenever I can and go into the college for a half day once every couple of months just to say hi and direct a couple of the instructors but thats it.No pressure to return from my employee either, thanks for that small mercy. I still haven't the energy to do a full day anything yet, but that's me. I hope you are the lucky one who bounces right back, but give it a chance and don't over do it. My talking days are done as my tongue still swells and I get mouth infections due to to the dry mouth constantly. You should fair much better so Plan away but remember we are are own worst enemy when it comes to work . We push ourselves too hard. Good Luck