As you said, there are so many "gaps" in our evolution that's impossible to have occurred just my natural evolution. From a cosmic standpoint, it's like the day before, we were hunting animals using stone tools and the following day, we were building pyramids and other megalithic structures. Someone said "Earth and Earthlings are the center of the universe". So many technologically-advanced species have their eyes on us for millennia but nobody knows why. Perhaps someday, we will find out, unless of course we blow ourselves up to kingdom come with our nuclear weapons beforethen.