I've dutifully kept bank statements for well over the 7 years that HMRC recommend but today I had to do something as my filing space was getting out of hand. I've been punting for around 20 years from 2002 so I decided to get rid of bank statements up to 2015. (A not inconsiderable mound of paper)
A brief review showed me the pattern of cash withdrawals I have made which last 20 has perhaps yielded a little how my punting has changed.
Without boring readers it tells me that I'm much more choosy who I see, I'm much more price sensitive as a 'consumer' and my most important points are that research in the sites and with fellow punters via this site and perhaps others is invaluable and finally if you do find a gem -keep seeing her and good luck,
But get that shredder going otherwise her indoors will question more than you would wish.