That is great. it is a huge blessing that he didn't seem to notice how impaired and non-engaged you must have been.
My kids were older when i started drinking seriously, and older when i quit. I thought because I drank in the daytime, while everybody else was at school or work, that I had them all fooled. When i told them that I was giving up drinking for good, they were unanimously thrilled! My secret drunkenness had apparently had a much bigger impact than I had realized.