HTML seems easy – and it is easy but only learning it to make simple programs. As you go deeper and build more complex pages, you will see how difficult and cumbersome it can be – since many different renditions are in conflict with each other – in simple English, different tags and attributes show the same text differently. So if a text comes under horizontal tag in its immediate <div> box and on the bigger box it comes off as vertical, then there is a problem.
Never stop learning
Technologies are always changing and nobody can predict what would be the next big thing. The worst thing you can be in is in a static state. Learn a little everyday, make it a habit to learn for atleast 1 hour a day and you would never be redundant. And have a great life.