I like to write in my Bible. Alot. Possibly too much. The reason behind me making a new Bible my "main" Bible often happens because I can no longer read sections of it due to notes and highlighting. I also try to legitimately date my notes so I have an idea of when I am making them.
Every few months I pull down an old Bible. I flip through the pages and see where I had made notes. I can judge, through the emphasis, where I was spiritually at the the time. I remember passages I had read and meditated on. My old Bibles provide an annotated version of my spiritual journey.
I also have a few Bibles which belonged to family members. It is a blessing to pull out one of my Father's old Bibles and read his notes taken during college, or my Grandfather's notes for teaching a Sunday School class.
In this age of digital scriptures, the only thing that concerns me is the loss of the physicality of scripture. Having a favorite Bible, reminiscing over the prayers ensconced within it, strengthens the soul. Each of us have these chicken scratched and day-glo colored memoirs of our faith journey.
As I have said before; write in your Bible and remember the time of spiritual growth noted in each and every mark. At the beginning of a new season, you now have a symbol of the healing grace of Jesus Christ to physically touch, see, smell and feel.