I take it for granted and forget what others who have never lucid dreamed before may think of it. So it's actually a good question.
When fully lucid, it truly is like living in the present, here and now, but in a dream environment. So if you remember what your dreams are like, it is pretty much the same. But instead of remembering them later, you live it as it's happening and can question it with a waking, lucid mind. (with varying degrees of lucidity which you may learn about later).
Sometimes it's like living another day while others sleep!
If you lucid dream every night, you live twice as long.