Everything was fine, but every time I start the Bitcoin Core, it take a hell load of time until it starts downloading the blocks, even after I've finished the initial bootstrap, as if you are forcing a car to move after letting a few guys give it a push.
Can you be a bit more specific on what exactly "a hell load of time" is?
For some people, given their setups/hardware, this could be 30 seconds... for others 10 minutes.
Also, is this once the GUI is nicely loaded and the main wallet window is open? If so, it might be a network issue. Check the "network" icon in the bottom right corner:
If it isn't showing any 'bold' black dots/lines, you're not connected to any peers (and can't receive any blocks etc)...
you can also check "Window -> Information" and check the "Network section" to see how many connections you have:
and also you can see the 'speed' of those peer connections using "Window -> Peers" and look at the ping times.