@Peter_G
Firstly, thanks for the welcome, and you are welcome back! 
This was not a pondered decision but it stemmed from the way that I was working and what I was interested in, back at my time at Wise.
My journey
I started as a Paid Social Exec, the most junior role in any team in performance marketing. I was always very data focussed, I studied Finance and Maths, so I have always been very accustomed to dealing with numbers. What was the turning point for me was needing to understand how metrics were defined, and coming up with new metrics that would inform investment decisions for the team. We used Looker as the data visualisation tool, and models were defined in Python and SQL.
I first started to define metrics for the team in LookML, which requires a data model to have been already built. There, you can basically grab variables from a table and actually add it to a Looker explore. This allowed me to break away from having simple things blocked by data analyst’s time variable.
I think I really wanted to push the team to start thinking about optimisation which was solely data driven and focussed. So I essentially asked for help to our data team. They essentially up-skilled me to learn SQL basics. And then from there it was a very steep learning process to become independent and push model changes to be able to quickly impact Performance Marketing’s visibility on data, and how they could be thinking about growth from a higher company perspective, not only driving user growth, but also product adoption.
So the change was a mix of grit and determination, but also having the right support system and opportunity to be able to dedicate time to this. My first project as a data analyst was re-writing all of the marketing models to make them more modular, write checks for data reliability and making sure we were not breaking models, and then displaying them visually for teams in Performance Marketing to use. I ended up giving a lot of 101s to the Performance Marketing team on how to use these data points.
Although it’s not my job now at Monzo, we have a very similar challenge, and I am fortunate to have exceptional colleagues with an insane breadth of experience to help me out on this. They are able to pick up on complex problems which I am very close to so quickly, I am always in awe of their work, and methodic approach to problems. 
Advice
- Find the right people who can teach you the raw skills
- Understand how you learning these skills can unblock people around you and have a positive impact on the company trajectory.
- Always explain what you learn to others because this will help you understand if you actually understood concepts properly yourself or not. The number of times I explain a concept to someone and half way through I realise “wait a sec, this actually doesn’t make sense” is innumerable.
Hope this helps, great question 
EDIT: I say “essential or essentially” a lot but there’s nothing essential about having great colleagues, that’s just luck!