Additive like: Let's say you shovel sand into a pit and you shovel 1% more than your peers every day for a year. By end of year, you will have shoveled 1% more.
Compounding like: You're a derivatives trader and make 1% more returns every day for a year than your peers. By end of year you will have made 3780% more.
Knowledge isn't perfectly compounding, but it must necessarily build upon previous knowledge. Abnormal levels of investment and dedication in learning definitely pay off in the long run and compound faster than you would think.
If you fix enough things, you build a collection of tools and techniques that let you fix just about anything. You also build a lot of confidence in your own repair skills.
Two years ago, I bought my first motorcycle. I was afraid to change the oil on it. I'm currently rebuilding a motorcycle engine. A lot of that knowledge carries to bicycles and cars, so in a sense, it compounds.
Beyond just sticking with it, you also need to continually challenge yourself. Avoid staying into the comfort zones that fear and ego will shunt you into.
These are very difficult to do as a beginner because you're going to encounter so many demoralizing roadblocks. I still remember when I first started writing code. It was incredibly painful. Things that now take me minutes would take days.
The real key here isn't some technique that will make the learning easier, it's in getting the emotional fortitude to push through these struggles. Your struggles will be unique and it's impossible for me to prepare you with solutions for every novel challenge you face. "Ask not for lighter burdens, ask for stronger backs" and all that jazz. There's a lot of resources online, esp. on Youtube, about increasing mental discipline. Cold showers, fasting, mental discipline, stoicism, etc. I recommend investing some time into trying these techniques for improving pain tolerance.
If you want to solidify your knowledge, make a 30-min talk for your peers about the topic. Commit to make it perfect and be prepared for their questions.
And remember that friendship must be actively maintained.
You have to be comfortable with making mistakes and being bad at things, because it happens a lot when you're just getting started.
I've found this mindset has led to some of my least healthy and least-disciplined decisions.
Then again, I think of "discipline" as doing the work to tend to the garden that feeds you. Maybe in your life-situation, you need to pass up the opportunity to play with a child.
That level of dedication came to me because I was not very disciplined when I was younger and hadn't developed any marketable skills. I grew up poor and I didn't want her to grow up poor. So I threw myself into something I had an aptitude for and I started working my ass off at getting better at it. Though, one could say that any effort is considerably more than I had put in before.
I really want what is best for my daughter. I have to give her a better life. So because it has become so important, that's why I work so hard. She interferes sometimes, but I'm not going to let that stop me from giving her a better life.
Not speaking from experience - I just have three kids, do what I can to take care of them despite being the primary breadwinner, and can't imagine the resentment that must stack up if you just drop all the sleepless nights and weekends of kid-juggling on your partner.
Never mind that you'll lose 7/8ths of the whole point of having kids with this approach, too.
But the biggest thing I did was get a job in IT. Then I went back to college. In college I think I work harder than most of my peers, who seem to struggle with something as simple as appending to a list in Python, or understanding a while loop in Java.
Meanwhile I am working on a portfolio so I can get a job as a programmer. Here's one of the sites I made recently: http://pichart.com It's not much, but it's a start.
What has been my personal compounding interest kinda thing has been architectural design, data modeling and databases (SQL), loads of things that are not exclusive to one language or environment.
I spend hours every day dedicated to doing things to improve my skills to become more valuable in IT. People think I'm crazy, but in the time frame I have begun to do this (since my daughter was born) I can now probably run circles around anyone else who would have started at the same time.
Hours of dedication, every day, is not normal. It's probably not healthy either, but I got a late start and I need to catch up.