For me there is no think about it attitude. I actually look FORWARD to going, and usually cant wait.
What I have found for most people that have the attitude you do is that they have something that is setting them back. Things you hear normally are...
1. My GF just broke up with me. (not motivated)
2. Its too hard (therefore i'm not motivated)
3. Its not fun and I dont enjoy it (not motivated)
4. I've been at it X months and I dont see too much (not motivated)
All those reasons make people go.... Ah forget it. I'm sure there are more, but you need to find something to motivate you.
I would always tell people to NOT make women your sole reason for lifting, but if you can use it to your advantage, then so be it. Picture this woman you want to be with and go.. you know I can get that if I looked good. So dangit i'm going to hit the gym.
Get a magazine and post a pic of a dude in your room (sounds gay I know) and go... I'm gonna look like that, and then hit the gym.
Again dont make this the ONLY reason you hit the gym, because then if you DONT pick up women, you'll quit, and go... That didnt work, then blame it on lifting.
The down side to all of this is, if you keep having that attitude as to why you look for reasons NOT to go, then you should take up something else. Because an attitude like that will get you nothing.
We can give you many reasons, but if you dont find one, or cant, pick up another sport. This isn't (as I explained in my school post) for the weak at heart, and isn't something you can go... Well, i'll go on Friday and maybe Tuesday, and take a week off, or drink myself stupid and go have fast food.
I will tell you one thing though. If you have that mentality when you wake up or before you go to the gym, your not prepared to go, and you might as well skip the gym because you'll be going through motions and that is it.
I keep motivated because I love it, and I do it for myself, and to prove to myself hey, this can be done. Also I am good at it.
I try not to be harsh on people, but sometimes I hear... This is too hard. Then go play in the sandbox or take up ballet dancing. No one said it was easy. Not saying your not motivated cause its hard, but MANY people say that. I just cant do it. Then you know what? FINE, there are those that will and it wont upset us. Hard truth is that not everyone is cut out for this, and that's the way it will be.