How many assemble their engines

Did a '71 318 for my '71 swinger. Followed a Chiltons best I knew how. Had shops in the town where I let do the machining, just the basic, no decking. Had rods recon'd, crank checked and polished, mic'd. All measurements were stock. Didn't know about....squat actually. Got it together and went to start it. Wouldn't fire, nothing. Checked everything and had gas and spark. Then I dropped the dist bolt on the ground, it was then I noticed ALL, well almost all my oil on the ground. LOL. Had to pull the engine again cause I traced it to coming from between the tranny and rear of block. Turns out the shop forgot a gallery plug on the passenger side by the cam, back of block. $1.00 and 1/2 hr later back with a plug in. Then back in car. Then found I had it out of time, #1 was where #6 should be........ I said I tried to follow the book the best I could. LOL Finally got it running, broke the cam in, and 1 month later drove it 1,000 miles back home. Ran for another 8 years until I moved to where I am today. Don't have the car any more. It seems the "welcome wagon" rear ended my car not once, but TWICE in a weeks time. I was so pissed!! That was my first car, with the rim blow tuff wheel, hood and trunk trim, rocker panel trim, wood grain on dash. I loved that car. Wanted to fix it up. Oh well, 19 years later I get the '70 I have today. Now I have a 340 to do, and I will do it myself except for the machining. I WILL do better because I may know more, but I know I don't know it all. Does that make sense? More humility today, ASK FOR HELP.