Manual versus other modes

[alsocass]

I have been working my way through the 'New to photography' book (fabulous by the way), and I want to understand a bit more about the prevalence of the different camera modes.

I say that I 'switched to manual' a few months ago, by which I mean that I stopped using the auto feature and started using the other modes. For me I wanted to throw myself in the deep end so I did switch to manual and have never changed modes since. I had an interesting morning a few days ago in which I took photos of my daughters in constantly changing light conditions (in a paddling pool partly under the shade of some fruit trees). The results were completely unusable, even as snapshots for the fridge, but I enjoyed the experience of having to constantly change the shutter speed and aperture in order to take the photos I want... it was a good exercise.

The books says this:

In practice most photography is done using Av or Tv mode; manual is usually only used for special reasons.
Some photographers use manual all the time (and usually made a big noise about this fact) but it is not necessary.

I have become a bit afraid of using those modes, as if doing so will plunge me back in the direction of the auto button. I guess what I am asking is ... is this true? Is Av and Tv the modes that I should most often be using? It would certainly make taking photos of my children easier. But is there any benefit to sticking with Manual while I am learning (I am starting to think it would be better from a learning perspective to use the semi-automatic so I can take better shots without having to focus so much on the triangle).