A few gigs ago, I had a boss who was trying to single-handedly move the organization in which he found himself into the future of agile and dev ops. This was 2012, and agile wasn't a thing enterprises did, let alone mid-sized adware companies.
Garrett (my boss) liked to talk about T-shaped people. "We need more T-shaped people in this company." We were always trying to hire T's, instead of I's.
I left that job -- not because of Garrett; he left a year before I did -- but I still think a lot about his optimistic, borderline quixotic quest, and his T-shaped people.
Last week, someone asked me what she should do to reach my level of
expertise with technology. I get asked this often, and I don't have a really good answer -- primarily because I don't think there is any single, specific thing that I did to get where I'm at. I think I just lucked into being a T-shaped person.
In my daily work, I bring to bear all manner of weird and unusual disciplines and experiences. I once spent a summer compiling Linux kernels just to see if I could do it. I tried to write a Zork-like adventure game using an Apple ][e and learned first-hand why functions and recursion are a good thing. Most of my troubleshooting experience, summed up as Check Your Assumptions, derives from a decade of making bone-headed assumptions and wishing desperately to avoid the embarrassment again.
I'm a T-shaped person, and if you want to excel in whatever you do, I think you need to be a T-shaped person too.