Evidence for the Forever block delay. Just go on the editor and you can easily understand what is happening. Clicking the flag, both the timer sensor and a variable Timer will start at 0, and the variable works in a forever loop where it is added 0.1 every 0.1 second - supposed to both timer and Timer have always the same speed, but as you can see in the Forever block delay (that is always timer - Timer showing its difference) it shows a lot of 0.XXX where it is supposed to be 0.
