Consideration is two-way. In a contract, I’m prepared to give something of value to you who, in turn, is prepared to give me something of value in exchange.
I give up something of value but receive something of value – and so do you
I believe you’re correct – except for the unilateral bit you put in.
If I’m subpoenad to attend in Court as a witness, I get nothing of value back in exchange for me giving my time.
Equally, a deed of gift ( another type of unilateral contract ) does not involve the beneficiary giving anything of value in exchange for the promise of the gifted property