From my limited understanding of Base Training, it can look quite different for everyone depending on your goals, the methods you use and how dedicated and serious you are. I have read bits of the book Base Training for Cyclists (pretty sure that's the right name). The basic idea is basically to build a solid layer of training with which to grow from to reach whatever goals you want to achieve. Like the foundation of a house.

Everyone who takes up cycling consistently, develops some sort of a base, no matter what they do (unless they lollygag every ride and never push themselves whatsoever). It just may not be as solid of a base as someone who is aggressively pursuing the strongest base possible for their specific body, abilities and goals.

Let's say a beginner rides her bike for a season and starts by riding 10 to 20 miles at 12 mph. It's the best she can do without having "any" base. By the end of the season she is riding 20 to 40 miles and doing it at 13 to 14 average pace. She is now at her fitness "peak" for the season and she has now built a base. She takes a break for winter. When she starts riding again in the Spring, she has lost "some" of her momentum. She can't go as fast as she was at the end of the previous season, but she is not starting all over again at square one as a beginner, because she has built some sort of base. She still has some of the strength and fitness she had achieved the previous season. It shouldn't take her "too" long to get to the level of fitness she was at her previous season ... and then hopefully build from there.

The book basically talks about seasons like this. You begin your season by building up your base, annually, not over doing it by simply riding as fast as you can every single time you ride. You use various training techniques to either build endurance, speed or climbing ability (the book recommends focusing on one at a time). You have goals of specific events you want to train for. At some point during the season you "peak". You are at your strongest for that season, and maybe ever. But you cannot maintain that strength year round. It's too difficult on your body, which needs some recovery time. Once you recover, you start up again and do it all over again, hopefully gaining more strength, endurance, speed, etc. with each season.

So there's my little tidbits on my understanding of base training. It sounds like you are going for it aggressively, so you'll probably get great results. Good luck!