Reason for eating greens?

So my bearded dragon I got in May 2016, she really had not eaten any greens at all until very recently. I tried putting worms in collared/dandelions as well as butternut squash and peppers etc. She would pick out the worms not eat any greens. I pretty much gave up on buying veggies, they'd always go to waste. She pretty much has eaten nothing but bugs.

Shes about two years old, and I decided to give it another shot the other day. I bought escarole and arugala and put it in a dish and went to work. It was all gone when I got home. Now anytime I put the greens in her dish she devours them.

Why did she randomly start eating the veggies after so long showing 0 interest? Is it because she didn't like collared/dandelions and likes escarole/arugala... or maybe an age thing?

When they are younger, they don't ususally care much for veggies, but as they get older they are (usually) more acceptive. At two years your beardie shouldn't be feed a ton of bugs, most of her diet should be greens. Adding colorful things like squash and carrots also help to 'spice it up'