Overall its good...liked it actually.You know the title was good.But I don't know why you changed it to "how can I forget those days" in the poem..but thats fine..A bit detailed,especially your "together phase"...
hmm..well y'know thats the reason the poem loses some credit I guess.You haven't given justice to the breakup..could've been a bit more dramatic..I mean you've explained your past in thorough detail but the breakup is just kinda vague and the poem ends suddenly..if you get that balance right then you're awesome...you could've skipped the second last stanza all together..but then again,don't..coz well,this is your poem..
Or you could decrease the pre-break up nostalgia (but still keep it as intensive) like madhuresh said so that the breakup would feel adequate..
What I liked..hmm..well,the simplicity for one.Its very nice..spontaneous sort of..the '1 by 1 brick' was nice but could've been framed better..again 'scars beneath my skin' was good but could've been framed better..nice work though..
Try the balance,otherwise I liked the poem..and this is a lengthy reply,didn't mean to say soo much..anyways,keep writing!!
"I feel like I'm number one,yet I'm last in line..."
"So I think I'll keep on walking,with my head held high...
And only God knows why..."
Only God Knows Why - Kid Rock