A question about half-pressed shutter and exposure lock

I finally understood your response readign another thread.

It should be:

1- Aim at focus point, half press to lock focus
2- Compose and shoot

Instead it's:

1- Compose, press AE lock to lock exposure
2- Aim at focus point, half press to lock focus
3- Recompose and shoot

So it is NOT possible to simply half press (AF) then recompose and shoot with exposure on full press. Why does it have to be so convoluted ??? I thought this camera was about not pushing too much buttons ... I was wrong