...and they don't change my profile and settings every couple of months without so much as a "by-your-leave."
I wouldn't count on it.
You're right, we don't have the original copies of the Gospels, only fragments from long after the supposed events. The only full manuscripts we have are certainly copies, and copies of copies, and copies of copies of copies, and so on. Such a route can introduce many corruptions and mistakes. However, New Testament Scholarship has been growing by leaps and bounds since the 20th century because more and more evidence (scrolls, historical documents) is being discovered. Along with that, certainty of their authenticity is growing.
Scholarly consensus is growing toward dating all four of the canonical Gospels in the 1st Century. For example, it's realistic to believe that the dating of Acts approximately lines up with the dating of the Apostle Paul's imprisonment in Rome (A.D. 62), since this is where the account ends. If Acts was the continuation of the account that Luke began in his Gospel account (see Luke 1:3; Acts 1:1) then Luke would be dated sometime before A.D. 62.
I would suggest reading some additional New Testament scholars to help balance out your view of dating. Here are just a few:
Other thoughts about the historicity of Jesus: First-hand witnesses could be considered reliable.
10 to the 12th power microphones = 1 Megaphone