Programming became a lot easier when you could just type a question into Google and it would find that someone asked the same question in some forum or newsgroup. In 2003 Google would always include results in a site called Experts' Exchange, which was basically an earlier version of Stack Overflow.
What was different, though, before Google, was that when I got stuck, I often spent a lot of time inventing (or guessing,) a workaround, and my workaround was often incorrect, fragile, slow, ect. In today's world, I'll often see the workaround show up on Stack Overflow first, and then a better answer show up, and then a better answer.
(edit) Another difference is that documentation is essentially annotated today. If the documentation is confusing or misleading, it's usually clarified in a stack overflow or some other forum. Before Google, if documentation was confusing, you were stuck guessing or hacking. That was very time consuming.(/edit)
So basically, before Stack Overflow / Google, there was no globally searchable database of questions and answers. You would get stuck on simple things for a long time, and move much slower.