Finding resources online is no longer a problem. It's (amaze) to see the resources we now have online for self-education. The possibilities are almost endless. You can learn just about anything online. Mention a subject and you will find enough materials (fill) months or even years of learning.
Since there are more than enough resources out there, what limits you is your own (curious). It is the fuel. The more you have it, the (far) you will go. It's like someone explores an open land without any border in sight. How far she goes doesn't depend on the size of the land on the amount of fuel she has.
While the resources are (actual) unlimited, your time is not. So your ability to choose what to learn (become) more important than ever. You should spend your limited time the right subject and with the right depth. Not everything is worth your time, and for those that do, each deserves different amount of your time.
Learning is a lifelong process. We are lucky to have all these resources and (opportunity) online. Don't waste them; make the most of them instead.