Assuming it's a morning race I guess I've left it too late to wish you luck for the 10K, but I hope it was an enjoyable and uplifting day out and you got a decent workout.
Re the half mara, the cutoff time adds a little spice and gives you something to aim for. It sounds like it will ensure you have to work that little bit harder, which is good for the steady progression that you are planning over the course of the year. You really don't want an over-attentive marshal pulling you off half way round the course...
Your success in training your brain to want to exercise reminded me of
this recent post by Scott Adams - see the paragraph entitled "exercise".