20 years worth of baptisms invalidated

I don't think this is true. The Didache suggests otherwise and it was written between the years 65-80.

"And concerning baptism, baptize this way: Having first said all these things, baptize into the name of the Father, and of the Son, and of the Holy Spirit, in living water. But if you have not living water, baptize into other water; and if you can not in cold, in warm. But if you have not either, pour out water thrice upon the head into the name of Father and Son and Holy Spirit."
I have never heard of "The Didache" before (I am not Catholic).
I did a quick google search, but would you mind providing what you believe to be an accurate link and explanation of it?
Thank you!