Do you brush your teeth every morning? If so, how did you develop the discipline for that?
IMO, there's even more similarity between the two. If you skip brushing for a day, you'll have slightly bad breath. If you skip a week, you'll have really bad breath. A month? You're looking at cavities. The longer you put it off, the worse it gets, the effects just aren't immediate.
The same goes for time management. Skipping a day is no big deal, but if you keep skipping, it only gets worse.
I do have two more realistic recommendations for better time management.
1) Pick a system that works for you and use it 100% for everything, not just work, or for home or any other subdivision, use it as your primary system for everything you need to get done. For me, I'm migrating that into the GTD system, and so far its worked very well for me. The important thing is that you stay on it, because if you stop using it at all, it won't work.
2) Don't half ass anything. What I mean by this, is consciously make a decision to fully engage yourself in whatever you do. Either be productive, or don't be productive, but _never_ anything in between. You made this post on a monday morning after spending a weekend watching tv and youtube and it bothers you because you feel like you wasted a weekend. The problem is you _did_ waste a weekend. Because you were sitting there watching tv and youtube while consciously worrying that you sitting there watching tv and youtube instead of being productive. Do one or the other, never both, if you're worrying about something, put it on your todo list and let it be until you're actually sitting down to do it. Its perfectly fine to spend an entire weekend doing absolutely nothing productive, but you need to make the conscious choice to do that and immediately drop any worries about doing other things.
I watched world cup over the weekend as well, I even played zelda on my DS while watching world cup, and it was great, I had a lot of fun, because I said hey, I want to relax and have some fun for a while, so I played video games and watched soccer with no worries about accomplishing anything or not being productive. I had made the choice to not be productive which allowed me to have worry free fun and relaxation. After the game I decided it was time to get stuff done, so I went to my list of projects that all have next actions waiting for me, so without having to figure out what needs to get done next, I had a task waiting for me and was immediately able to jump in.
So overall, it really is a mindset change, with the most important aspect being able to focus solely on your current action without worry.
Take for instance this weekend, I had a whole vision of what I was going to do over the weekend and what I was going to get done, it was great, it sounded like a perfect plan, except none of it happened, life happened. I got caught up doing other random things that are on my ever expanding todo list. That doesn't mean I didn't have a productive weekend, on the contrary, I got a ton of stuff done, and I'm sitting here on a monday morning calm and relaxed knowing that I had a full and productive weekend and that I'm ready to get more stuff done this week, whatever it may be.
The best advice I can give you is to get a solid time management system like GTD setup where you dump everything, and then stop trying to allocate your time exactly, but rather think of things in terms of actionable steps on a variety of projects, so you can just jump in and get something done. I find having a specific project that I've been hyping up getting done all week rarely gets done because you've thought about it too much. You just need to act.