Car Battery

Sorry I forgot to take pictures of the snow storm in our city : ( but I have a reason:
The day after the snow storm, I tried to unlock my car but my car didn't open - so I had to open it manually. I noticed that I forgot to turn off the headlight :( :(
My class started at 9 AM - it took me 45 minutes to get there, so I used my free time to jump start my car but it still didnt work : (

I am so bad - this was not the first one. Two days ago I also took V's car and forgot to turn off his car headlight : ( We had to jump start his car - Fortunely his car started immideately unlike mine, otherwise we won't have any car last Friday.

Maybe it is time to replace my car battery - or attach a postit on my stearing wheel so I remember to turn off the headlight