What Eddie said. The thing is, if you were caught, you could hardly deny it. Accepting a caution ends it there and then, unless you would want to go through the lottery of a court and name in the local paper etc.
One thing this highlights though is that, whilst some may view you as getting off, the reality with any caution or conviction is that it affects you in various ways. The latter particularly with getting insurance, virtually any job, credit. The list is endless.