Well, a lot of people observe Lent, and for a lot of reasons. (I've even noticed a growing number of non-Christians observing it.) Some people do it as a way of bringing unruly desires under their conscious control, increasing their level of self-mastery and winning themselves a measure of personal freedom. Certainly when I was younger, and even more of a slave to my baser instincts than I am now, that was my goal.
It's a little different now, however; at any rate, I frame it differently.
A colleague of mine says that "we give up what we want most for what we want now." I genuinely want to read that book about Aristotle, but with a Christopher Moore vampire novel at hand, that's going to be a challenge unless I give up fiction for Lent.
There's less to be gained by walking to church for morning meditation if I stayed up late the night before watching Netflix than if I'd gotten a good night's sleep and came in fresh. I genuinely want a fruitful meditation time, so I give up Netflix for Lent.
Time spent on Facebook, while I enjoy it, is time not spent on musical and writing projects, so away Facebook goes for a while. That way, when Easter comes, I can meet it as something closer to my best self than I was forty days ago, having spent that season of preparation trading in what I want now for what I want most.