I do not recall ever having done that... finish a book and then immediately begin it again that is.
Actually there are not that many books I've read a second time. I have posted here that I read The Lord Of The Rings every couple of years, Christmas time. Used to read it every year.
I have read Lonesome Dove several times... but not as much as LOTR. I've read it maybe... ohhh... somewhere between 5 and 10 times. Same for Watership Down.
Most of the books I've read again are non-fiction... and most of those were Civil War novels. - JamesJM