Just sent a small sum to an address for a check, the machine answers that there is now 0 BTC on that address FROM where I sent money.
So I went to a block explorer to check this damn address: 14U61He6rNdgfDBtE2vuytaaDH3y3fHZhU
And I see this: https://blockexplorer.com/address/14U61He6rNdgfDBtE2vuytaaDH3y3fHZhU

The problem: I have no money on that address. I have never received any BTC on that address.
I checked ALL the addresses in my Bitcoin Wallet, and I didn't receive any money to that address ever.

And it emerges: it seems I didn't understand shit of the blockchain.

Address 14Tf is the one that is SHOWN in my Bitcoin Wallet.
As I didn't move a lot of money from that address, I would assume that the money is still there.
But it's not.

Apparently, when I made a small transaction of 0.01 BTC to 14NF to show a friend how Bitcoin works, THE REST of my funds were moved to 14U6.

Then, I made this small transaction of 0.001055 BTC to 14FG and AGAIN my funds were moved onto another address: 1LNz.

Can please somebody with good hearth explain me why oh why if I make a transaction, all the rest of my funds is moved onto another address BUT it doesn't show up in the Bitcoin Wallet AT ALL?