Still, we managed.
If you’re going out on location, set up all your gear first, at the studio or at home, and then break it down into your van or car. This way, you know you have everything you need in the transport vessel.
The odds of you leaving a Critical Piece of Equipment behind are directly proportional to the distance and difficulty of reaching the location. If you’re shooting in your living room, no problem. If you’re driving two hours down the freeway, another two hours down dirt access roads, and hiking an hour up a mountain, you will leave something behind that you really really needed.
Of this I speak from experience.