I know it is jaw dropping but given the many reports of how he assaulted women, even his own wife it really does seem that for once he may have been telling the truth. However given his pathology it actually isn't surprising if he thinks that what he claimed makes him look good.
Actually, it's always been entirely clear that the "grab 'em by the ____" line was a deliberately humorous self-reference right back to what he'd said immediately before. He said "you can do anything" and then he realized "anything" was a pretty big claim, so he instantly gave a deliberately over-the-top example of something calculated to sound silly and humorous. He and Bush were very keyed into one another, he was enjoying making Bush both impressed and amused and he was caught up in his own sense of humor and having fun with what they were saying.
They were enjoying the thrill of knowingly being crude and "naughty" - I think there was a degree of self-awareness in it. It was self-indulgence in saying things they both knew were very un-PC.
I've joked around with guy friends enough to know how this stuff goes and I could read it in them.
I firmly believe "grab 'em by..." was willfully silly and over the top, demonstrating the absurdity of claiming literally "anything" would be permitted.
The large nugget of truth in what he was saying, however, was that yes - he had decades of experience seeing women throwing themselves at him because of his fame and fortune and probably a pretty solid track record of taking an interest in a woman and ending up getting to have sex with said women after putting in fairly minor levels of effort, which he correctly attributed a large part of to his fame and fortune.
I don't actually think he's really the assault type. The awkward Stormy Daniels encounter (which I think may be true) is probably more characteristic of how these things played out. I will concede that when he was substantially younger, back in the 80s or something, he might've been more physically forward and bold about these things... but I doubt he's ever done anything criminal which would qualify as sexual assault.
And again, people always conveniently try to exclude the "they let you do it" thing - he wasn't literally saying "I go around and grab random women's crotches with no prior indication of consent, and every time it turns out that they were okay with it because I'm famous." - No, he was saying
"when I'm interested in women, my fame and fortune tend to mean that I don't get a lot of pushback and I tend to get my way most times. Now that I've said that obvious truth, let me get a laugh out of you with an amusingly absurd way to demonstrate that concept."