it has been some time+since是什么意思

it has been some time+since 是“自从什么什么事情之后已经有一段时间了 ”的意思.
I realize that it has been some time since I have “我认识到自从我拥有.已经有一段时间了”,我不知道这个句子是否完整,所以就这样子理解的.