The complexity is what keeps them interesting to me. I'm a year and a half in and still feel like I know a little more than nothing but still a 100x more comfortable than when I started.

If you're new, first take minimum path to get game working and no more. Always work on just one thing at a time so you know that if something just broke it was the thing that you just worked on. Single players much easier than multi. Try to start with games in good condition or even 100% playing if possible. Once working, rebuild flippers, pops and other simple things one at a time and your confidence will slowly grow. Have fun with it! It's a great hobby.