Why don't you do the things you know you should be doing?

I am not always able to motivate myself into doing them.
There are times when I do feel motivated, but these of course are usually times when I am not in a situation to do them.

At other times, I just find it difficult to get myself motivated enough to start.
But, when I do manage to be motivated and start the work, I try and usually do get as much done as I possibly can, just to take advantage of the current motivation I feel.