i learned that if you put on the passenger side header first, then you cut your hand removing the header so you can put the drivers side on first! I learned that when you tilt the engine with a floor jack to fit the drivers side header, with the car up on ramps, you end up using an engine hoist after the engine falls off the floor jack almost catching your fingers between the mount and the perch. I learned that header bolts, when dropped, bounce off heads and vanish! i learned that you can dump a motorcycle onto your wife's car and break off a mirror just because you want to get a socket on the far side of the bike but you don't want to walk around it, so instead you lean over top of it and tip it (and you) right over! I learned that there is a limit to how much of my own stupidity i can dish out before i disgust myself and head inside to bed!
After you do it a few times you find a sequence for doing things and you know what tools to keep handy. Believe me, the first times the hardest.
Hey dont feel bad I did the motorcycle thing as well and it hurt like hell. Boy did I feel dumb when it fell over and I landed on it. Cost me 2 signal lights and big bruise on my chest and EGO. Lost dozens of bolts and sockets into the depths of hell over the years. Funny how they just seem to vaporize aint it. Wonder how many 8mm sockets I lost over the years????