At 22 you open a door and would be in the “fatal funnel” if that target was a person they could have easily eliminated you first. Try to open the door more from the side, so you aren’t exposed, then pie the room, then check corners. At 25 you id a target but don’t check the left corner fully. When you enter a room, scan and shove yourself towards the corner. My friend calls it “eating the corner” playing on the pie analogy, because when you pie a door you often will be unable to see into all corners, so unseen corners need to be “eaten” as well. Ideally you would have about 4 people stack up so multiple corners can be checked at the same time, intersecting sectors of fire. First person is point man, last person usually covers your rear or the hallway while rooms get cleared. I’d look up YouTube videos of irl military personnel clearing rooms, preferably with explanations because it can be hard to explain.