2014 - What OpenGL versions should I target?

As someone who is currently learning the basics of the programmable pipeline, i.e 2.0 to 3.2, and given that my computer only supports up to version 3.2, which range of OpenGL versions should I target? I was thinking of targeting OpenGL 2.0 minimum, however I realise that it’s getting very old now by todays standards. I’ve looked around and found similar questions that are 2-3 years old, most of which suggest targeting a maximum of 3.3, which would have made sense back then. Times have changed though and the most recent version is 4.4, so which version(s) should I target? Should I go as far as aiming to target 4.0?