The idea of the T-shaped professional, or T-shaped skills, is that you have one deep skill (vertical) and a wide range of other skills (horizontal).

Depending on if and what kind of education you followed, you’ll probably have a couple of things you know and one or two core skills. Over time, when you’ve been in a job for a while, the easy route is to keep working on your core skill. This is something you already are good at and developing this skill probably helps you in your current job as well. Becoming a T-shaped professional means that you’re going to actively invest in skills outside of your core.

Why would you want to become T-shaped (next to the fact that it is fun to learn new stuff)?

1. It helps you get better at your main skill. The knowledge you gain by investing in a completely new area helps putting core-skill tasks in a new perspective.
2. It makes you ready for the future. Jobs are changing and the world is too. A broad range of skills allows you to be less dependent and more flexible.

Don't forget: mastery is really important. I’m focussing on the horizontal part, but you know what they say: “jack of all trades, master of none”. It helps if you know your primary skill and make time to keep growing at it.

Make it a goal to set aside some time to engage with a completely different skill. Just don’t lose your curiosity. Or, as Jobs said: “stay hungry, stay foolish”.