I started journaling in high school and found a very effective medium for it: a dedicated gmail account.

I created a new account only for this, and periodically send emails from that account to itself, each email representing a day and having a subject line of the form "July 20, 2016".

Since the account has never been used in any other way, the inbox becomes a pure index of dates, and the account receives no other messages because no person or service is aware it exists besides me.

Advantages:

    --nobody can find it lying around    
    --inherently passworded    
    --nobody can ever even know it exists unless I tell them    
    --indexed, searchable.....can't tell you how wonderful it is to be able to type in a person's name and find the day I met them, years and years later.
    --never gets damaged or lost: it'll go down when gmail dies. not anytime soon.
    --infinite "pages"
    --accessible from anywhere

It's been wonderfully rewarding. It isn't until you start keeping a journal, and have had it for quite some time, that you start to realize just how much of your life you forget. As soon as you reread something from a certain day, you might think, "Wow! I totally forgot about that!" but now the memory is reawakened, fresh as yesterday. The memory was still there, hibernating. It might have been lost if you hadn't dusted it off.

But then there are many other memories, from 7 and 8 and 9 years ago, the small day-to-day interactions, the smaller subplots in the greater storyline....that may as well be from someone else's life. I know the places and people they're describing, but I have no memory of having done these things anymore. It's a little sad in a way.

I'm glad I keep a journal. 10/10 recommend even if you only update occasionally.