Let's talk classical physics for a moment: F = m * a . Force is mass multiplied by acceleration. How much force you need to apply to something to change its speed is proportional to its mass and to how much you want to change it. This formula describes inertia - the resistance an object has changing its state of motion or rest.
If your car is headed in a sound, good direction, then inertia is a good thing - it keeps you from getting blown over (a lightweight vehicle is more prone to winds for example). That is, until it comes time to stop or change directions. And unless you're driving across Manitoba on the TransCanada, you're going to need to change directions.
There's another point here too of course - the sister of inertia is friction. In a system where two otherwise similar objects are moving along, the heavier one will experience more friction. The net loss in speed should be the same if the objects don't have any additional force being added. But if they are being driven by a motor, the heavier one needs more force to maintain its speed in the face of friction. In short - if you have two objects both being pushed with the same force, the more massive one will move slower. Given the same input force, the more massive object may come to rest while the less massive object may keep moving forward.
Your life plays by similar rules. The objects in your life give you mass. I'm mostly thinking about physical objects at the moment, but it applies to other areas too (your friends and acquaintances for example).
If your possessions are mass, then the world is full of friction. The friction coefficient changes often (rough in hard times, smooth in good times) and it's hard to predict. Adding more mass is all fine and dandy, as long as you plan to keep upping your force to match and don't try to change directions too quickly.
Of course, maybe you're like me and you have decided you're having a hard time adapting to new changes. Or maybe you're realizing that you're starting to slow down and want to get back up to speed. Rather than looking for ways to increase your force, you could instead look at ways to reduce mass. Even if you do increase your force to go along with it, reducing mass will mean even faster acceleration.
Beware especially of things which have a built in system to get you to add more mass. A TV is only so good without a console or a DVD/Blu-Ray player to go with it. And once you have those, you'll need games to play and movies to watch. Or maybe you'll just sign up for a monthly subscription for cable television. But then you might turn to TiVo to record your favorite shows, or Netflix for streaming content.
Before you know it, you've invested twice the initial cost into something in order to be able to get its "full value". Buying the movies without watching them is pretty pointless though, so now toss in dozens or hundreds of hours of time into it.
And you know what - I've done it. I've fallen for that whole trick - hook, line and sinker. And I probably still will at some point in the future (or the very recent past - oh hi Skyrim). I'm not above the sudden, compelling urge to acquire material things. But I've started countering it by using its worst enemy - getting rid of things.
I have far too much stuff in my house (which is one of the reasons I haven't downsized my living space yet). So I'm working on reducing it. Aggressively. We're talking bags and bags of stuff I once thought was "so amazing and awesome" but now is more in the ballpark of "hey, I haven't seen/used this in years". Trash, give away, donate or whatever - just get rid of it as fast as possible. I've been probably overusing the trash mechanic, but it helps keep me from balking or chickening out.
Once it's dans la poubelle (as they say in French), it's not my problem anymore. An immediate kick of juice for it being gone, then tie up the bag at the end of the cleaning session and throw it in the bin outside.
So try it. Start making your life simpler by reducing the mass of your life. Some of the best things to throw out are the ones that keep waying you down with regrets for not using them more often. Fire your possessions.