The former Netherlands boss has enjoyed a positive start to his Untied tenure on the field, with friendly victories over LA Galaxy, Roma and Inter Milan (on penalties), but insists that he should not be expected to provide immediate results.
Van Gaal has already stated that his Manchester United squad is "broken", and also admitted concerns over the imbalance of a squad that the Dutchman feels contains too many No. 10s.
His latest quotes will again be taken as a bid to dampen the growing expectation over the club's potential resurgence after finishing seventh in the Premier League last season.
"Every club where I have been, I've struggled for the first three months," Van Gaal said.
"After that, [the players] know what I want - how I am as a human being and also a manager because I am very direct. I say things as they are so you have to adapt to that way of coaching. It's not so easy.
"The way I train and coach is in the brains, not the legs, but the most important thing is they have to know why we do things. When they do, the footballer is not playing intuitively.
"A lot of players are playing intuitively and I want them to think and know why they do something. That process is difficult at first and in the first three months. It takes time."
"When we survive the first three months, it will be the same as for me as it was at Bayern Munich," he added. "At Bayern, after the first three months, we were sixth or seventh and we were third in our Champions League group.
"We had to win at Juventus and did - that was the turning point. Now United have me, a new manager, so new chances for the players but we have to create a way of playing that isn't the same as before and that's difficult for them.
"They have to perform under pressure and have a to decide [what to do with the ball] within one second and that is not easy."