After the hatch imploded and Desmonds mind jumped into the past why didnt he need a constant at the time to stop it like how he needed it during season 4? After he was hit in the head in the bar in the past his mind jump just stopped where in season 4 they kept happening until Penny became his constant. Also with his visions of Charlie's deaths why did he keep only having visions of Charlie and only his death. Are these visions really from nemesis or a result of the implosion of the hatch? Just a coulple questions that have been bugging me since re-watching all of the seasons.