[[Dear Sister, I was wondering about something you said [recently]. If a person wants to become a diocesan hermit and needs to learn about the vows how do they do that? Also, if c 603 hermits are religious like all religious do other canons apply to their life besides c 603? Which ones? Will my diocese expect me to know all these things before I petition them for admission to profession? It seems to me that unless a person has been a religious in the past there is a lot to learn. I wonder if it is really possible though I know you say it is!]]
Good questions. I think your diocese will require that you have lived the silence of solitude as a hermit for some time before allowing you to petition for admission to profession. Certain things will be part and parcel of that including living a simple, God-centered life, of assiduous prayer and penance which is withdrawn from that which is resistant to Christ as well as from some of those things which are good but not really meant for hermits. That period will also be expected to be under supervision and receive regular spiritual direction. I think they will also expect you to understand and have lived the vows in an essential way before admitting you to temporary profession. They will expect you to have lived and studied the vows with all that means both theologically and canonically before admitting you to perpetual profession. (As you surmise, those who have been members of a religious institute will be ahead of the game, though applying what they know to canon 603 life will still need to be done.)
Remember that all of this will take some years and you will generally approach things in the stages I outlined. It needn't be as overwhelming as it seems to you at this point in time. One of the ways you will demonstrate your understanding of the vows (and also gauge your own understanding of these) is by writing your Rule. (Your Rule will provide a brief theology of the vows as you understand and live them and will include your vow formula.) But how do you get the understanding you need to do that? I think there are two main ways.
The first is by reading, reflecting on and living what you read --- and then reflecting on that as well. There are a number of good works on religious life and the vows, usually therefore on the vows in a communal context. Still, except for the vow of poverty which needs to be justified and conceived somewhat differently for someone living a solitary life, they work well for the hermit. The best I know of is that of Sister Sandra Schneiders, IHM. A good introductory and summary volume is New Wineskins. Sandra also has a trilogy after that with each volume named after the parable of the pearl and the field. Volume 1 is called Finding the Treasure, Vol 2 is Selling All, and Volume 3 is Buying the Field. You might start with New Wineskins. Another work on the nature and content of monastic profession is Centered on Christ, A Guide to Monastic Profession, by Augustine Roberts OCSO. This is one of those books I read and reread periodically. It is especially apt for any canon 603 hermit despite its coenobitical (and Benedictine) context. A final suggestion is the work, Christian Totality, Theology of the Consecrated Life by Basil Cole OP and Paul Conner OP.
The second way (and one which would need to be complementary to the reading you will do) is meeting regularly with a vowed religious for discussions on the vows and their content. Some of this may be possible with your director but more likely it will require your arranging something -- possibly with the assistance of your diocese -- with someone doing formation for a religious or monastic community in your area. This is a good place to become informed of and acquainted with the other canons which apply to consecrated eremitical life --- especially in terms of the vows. Further, and more importantly I think, it is a real gift to be able to see how others live the vows and an especial joy to hear them reflect on their meaning in their own lives and the lives of their institutes. Not only does every religious reflect on these vows (thus their minds, hearts, and lives will have moved in directions and to depths you too are invited to go in time) but it is important to understand that what you are being called to live is something you do in a kind of solidarity with all these others. I think any solitary hermit will find this consoling and empowering.
P.S., as noted briefly above, other canons do indeed apply to Canon 603 life. I will say more about that either as an addendum to this post or in another post. Sorry for having skipped over that part before publishing this! Check back in a day or so for additional information.