Unix has always fascinated me. I was hired to be a Unix communications programmer in 1986. I taught myself C, learned the X.25 protocol, HDLC, the seven layer ISO model and started struggling with the bourne shell. By this time I had been coding for 11 years, having started with BASIC in 7th grade.
What stuck with me through all the years and versions and languages and floppy disks is the incredible versatility of Unix. For me there was, and is, a fascination with using free tools on inexpensive hardware to do impressive things. Fast forward 30 years. Unix has become Linux, and it is running on an amazing variety of devices. The source code can be customized by anyone. New lineages of Linux have emerged.Some are highly specialized, some are more generic.
I run Linux on a half dozen platforms at home. It is a great way to tinker. It is a great outlet for curiosity. Here are a few of the examples.
Raspberry Pi - I have a model 2 Raspberry Pi running Raspbian (A branch of Debian). It is about the size of a credit card and has 1 GB of memory. It runs a twitter account that spits out a Game of Thrones quote each hour (http://www.twitter.com/BarryPi), and hosts a web server that will provide a random quote (http://GOTQuote.DuckDNS.org) and sigil from the series. This server also runs the network computing software from Berkley called "BOINC", which is a distributed grid computing environment. I participate in three projects on this server: Looking for pulsars in space, solving the original enigma code from World War II and looking for asteroids. See the list here, and look for the ones with the RaspberryPi symbol: https://boinc.berkeley.edu/projects.php
Late breaking note: My daughter just gave me (for my birthday) a Raspberry Pi model 3. Wifi, bluetooth, 4 USB ports, overclocked, all in the same form factor. Sweet!
Pi Top - The Pi-Top is a crowd funded (https://www.indiegogo.com/projects/pi-top-a-raspberry-pi-laptop-you-build-yourself/x/6731763#/ ) RaspberryPi laptop. The version of the OS is not too great, and the keyboard is abysmal, but it is an interesting package. Fortunately it runs the standard Raspbian distribution too, albeit without the battery management functions. I use it as a TOR relay (don't tell Comcast) and shovel about 8 GB of encrypted data through it a day for anonymous darknet users all over the world. Thats all it does. For now. See here: https://www.torproject.org/
Ubuntu - I run version 14 (in long term support) on a old Sony VAIO laptop. On this I run the BOINC grid computing software and participate in projects to map cancer markers, sequence the ebola genome and do AIDS research. There are over 700,000 volunteers in this program, through the World Community Grid. See here: https://secure.worldcommunitygrid.org/index.jsp This is all very legit research for which there doesn't exist enough super computer power in the world. The workstation also runs background music for me and runs the TOR browser so I can anonymously and confusedly surf the deepweb.
Netbook - Remember netbooks? I came across a ATOM-powered tiny little netbook in my home office the other day, an ASUS 900e. Circa 2009. A quick google search revealed not one, but several Linux distros that will run on this unit. The easiest, named EasyPeasy, is a custom package of Ubuntu made for this line of ASUS netbooks. In about 30 minutes I had Easy Peasy installed and working. I have yet to task it with anything but hey, it has wifi, ethernet, three USB ports and a 6 hour battery. Sky's the limit. Find it at: http://www.geteasypeasy.com/
So, to sum it up...
You don't need expensive gear and proprietary operating systems to do impressive things with computers. RaspberryPi computers are $35. The old laptop is, well, free. You get the point. What you absolutely need is a curious mind.
Be curious about something, even if it isn't computers! Or, in Linux-speak:
sudo apt-get update && sudo apt-get install curiosity