Keeping records is critical to serious shooters. You don't need to keep targets, if you kept a score/data book, (and done right) it would have all the information from the targets recorded. Recording shots doesn't help much if you don't record your calls. (calling the shot, or remembering where the sights were lined up as you pulled the trigger). With out calling the shot, you don't know whether the recorded shot was a flier caused by the ammo, wind, rifle, etc.
Record keeping keeps track of zeros and tells you when your rifle is going south. It tells you your zeros at different positions, ranges, weather conditions etc etc.
I don't think you can record too much information, as one old coach use to say, if a fly farts as it flies by you, write it down.
I have score books from 30 years ago. Score/data books are one of the most important pieces of equipment available but much be used right. Below is an article from the AMU regarding score books, it talks about High Power Rifle but it applies to everything you shoot, rifle, pistol, small bore, air rifle, everything.