Worth also mentioning that unlike the piston engine you'll be used to on cars and light aeroplanes, jet engines have a fairly large "spool up time".
I'm not sure what it is on the big jets, but I remember it becoming very important once on some work I did on the Hawk where the time from idle to take-off power was about 8 seconds. That could at-least contribute to a perception of a delay in applying power.
G