If you become big stack after winning a huge pot, and then you start playing very dumb poker, there are two possible reasons:
1.-You went on tilt: this is not just caused for being the big stack. Going on tilt on that situation is generally a consecuence of winning a big pot, even if after winning that hand youīre not big stack. When you win a huge pot, if you donīt control the emotion and adrenaline running in your body, youīre probably going to committe mistakes or play in way you wouldnīt play if you were "cold". Is exactly the same effect as running into a bad beat, but because both situations are so opposite most people donīt think that it can carry the same tilt effect, so they just donīt recognize that they are on tilt.
So if you have this problem you have to treat it in the same way you would do after a bad beat: Fold some hands, clear your mind, try to forget about the particular situation, let in the past all that adrenaline the most important thing is to focus in your game. A good book to learn that is "Zen in the Art of Archery" (i havenīt read it all but it has some interesting things that you can apply to poker, like to focus on what youīre doing, learning patience and all you need to master an art).
If you are able to manage your emotions and not going on tilt, but you are still losing after you become big stack, then your problem can be explained by this:
2.-You just donīt know how to play big stack: tenbob said it very well, "Yes it is the big stacks job to push the table around, but he didnt push anyone at all. He simply called off all his chips." Most people believe that being big stack means to limp in every hand and call every raise in hope to catch something. Thatīs wrong. Being big stack means that you are able to take control over your opponents putting pressure over them. You donīt have to be a calling station, instead you have to be an aggressive machine when itīs necessary. You have chips to make raises to put your opponents on uncomfortable situations. Make them think that if they enter a hand against you they have to be very careful, because you have the power to bust them.
That is not so easy as it seems, because you need to learn the right moments where you must be the aggresor and put pressure on your opponents. Most people donīt understand that and they just lose their chips by making stupid calls instead of using those chips to put pressure. In my case i donīt know how to play well being big stack, so i try to keep the tight-aggressive line, doing some moves that i think a big stack should do, so i can test and learn if they work correctly (that is one of the 2 ways of learning: practice and studying).