I had to do that whole shouty thing, as it's a massive lesson I've learnt. I have one whole wardrobe and most of another one just full of stuff I really don't need and on reflection simply shouldn't have bought. This ranges from clothes that I rarely wear to tools I don't need. To general stuff that only serves to fill spaces that would be better left empty.
So learn from my mistakes. Lets look at knives as an example.
Ok - knives are vital in bushcraft. They are our ford transit - our ubiquitous do it all tool. But there is no reason in the world to have more than 4 for general bushcraft stuff that you may do as a hobby. By that I mean the odd bit of wood work and craving, preparing the odd bit of small game, etc. If you butcher a lot of game then you'll need something different. If you carve a lot then ditto. But for all of the people like me 4 will suffice, and if you are just starting then I would say get only the first 2. Wondering out loud if others will agree with me...
1. Cheap as Chips General Purpose Knife
On my first ever bushcraft course I got one of these and I still use it more than any knife I own. If you are just starting then you will need to learn to maintain and sharpen your knife. This is only a tenner and if you ruin it or forget it'll rust if not looked after just get another one. I have butchered a whole deer with my one of these and carved spoons and made shelters and cut leather for leather work (could co on forever).
2. Well Equipped non-locking Penknife
Something like one of these. This is something that you can take with you pretty much anywhere and not worry about it. It has a small saw and a couple of blades. With care and common sense you can do a lot with one of these. I have one similar in my pocket almost all the time.
3. Carving Knife
If you do a lot of wood work and carving you'll want something that'll do fiddly stuff. I use a mora carving knife like this and it is the sharpest knife I have, and I keep it that way. In fact it is generally so sharp I treat it with special care. It'll do fine carving better than the cheap as chips knife.
4. Spoon Knife
A spoon or crook knife will do what is very difficult or time consuming otherwise. It'll let you carve the bowls of spoons really easily. That's why it creeps onto the list.
I have a toolbox full of knives that range from the cheap impulse buy to hand make knives that I saved for and the only way I differ from that list is I have a knife presented to me by my work for a 10 year long service award. This I had custom made and only because I have small hands and using the el Cheapo knife for long periods hurts them.
So anybody want a second hand knife - I've got a few going spare...