I think that anyone with any interest whatsoever in Reiki should at least complete level one training regardless of mental disposition or personality type. From there you can decide just how far you want to take it in your present lifetime. But just because you're not out there healing cancer or facilitating profound personal or spiritual experiences within yourself or others does not mean that you will never do so.

I think that some people are a bit misguided by the apparent ease of Reiki, and think that it does not take any effort. But it is also a mistake to think that once you are attuned to channel Reiki, you must dedicate your life to practicing it and open a shop or begin teaching classes.

You don't have to force yourself into some perceived model of what you think a Reiki practitioner should be. Just be receptive to the energy and let it into your life. It will find a place in you and you in Reiki. Everything has a time and place, and throughout the process of life, we are all teachers, learners, and doers.