If you could travel in time, where would you go and what would you do??

I've been thinking about this after looking at my ratings for a few years and seeing that I give very, very few 5 star ratings.

I know what the reason is. Books that have a significant impact on me, on how I think about life, literature, art, and the like...books that I am still thinking about long after I turn the last page...those get 5 stars from me. They're at the top. It makes a certain sense, then, that books that don't reach that level of impact but that I nevertheless enjoyed (sometimes a great deal) can only be 4 or 4.5 (depending on whether the site allows half stars) or lower.

Of course, not every book is meant to impact me in the way described above. Some books are meant just to entertain, to be light, and I enjoy those books a lot. I've thought about adjusting my rating system such that each book is rated in the context of what that book is trying to achieve. But star ratings don't allow for any granularity, so I still lean more toward the system I've been using (where 3 and above is a good rating).

What do you all do? If a life-changing work of art gets a 5 from you, does something that falls short of that automatically come in below 5 stars or might a gripping thriller that you loved but won't remember in a year also qualify for a 5 based on the fun you had?