Dacey's speaker is describing herself honestly, and she knows she isn't easy. She daydreams, blocks people out, and puts up walls. She finds it hard to laugh and says she's not easy to crack. Yet underneath the warning is a plea. She asks someone to be her "solid ground" when she falls, and to break down her walls rather than accept them as a reason to leave.
The tone mixes defensiveness with hope. She admits that many people have tried to reach her and failed, and there's a tired, slightly wry acceptance in that. The closing lines sum it up: she's "hard to love" because anyone who wants to must "do all of the above." The title, "Check All Of The Above," works like a test question, with every answer required.
The mood is vulnerable and guarded at once. The speaker seems to want someone patient enough to stay, but she is wary of being let down again.