I've found that I've often wanted to learn something new, but after the "honeymoon" phase, the novelty wears off and I don't sustain the discipline required. So now I tend to treat any casual interest in something new as just that. Things that I've learnt as new have often been driven by a real need, driven by some other burning desire. For example I learnt about CSS because I needed to make changes to my website, and I was deeply driven about making my product successful. Or I learned SQL because I was interested in getting a better job as a data analyst (and was frustrated by what I was doing day-to-day).
There are some people who learn for the sake of pushing themselves outside of their comfort zone, but they are committed to improving themselves in that way. If you've become lazy then it's a combination of no push away from the status quo and no pull towards something you yearn for.