NO, you are not ridiculous! I know we had a lot of posts with that same question.
She is probably impatient for the milk to start flow fast. When it starts slowing down she gets impatient again. To help with a better flow you can use breast compression to help her get out all milk you have in your breast. Visit
http://www.kellymom.com/newman/15breast_compression.html to find out more on it.
If she is so impatient before let-down you could pump and offer her your breast as soon as you get a let-down. That's how many babies act when they are ravenous. I also think that with time she will learn to wait longer and won't bob on and off.
Also, it is such age when they get so interested in their surroundings that they can become distracted and forget to do their "job" :lol: .