Is he a liar? am I stupid for staying with him? is my gaurd up too much?

i've been with my BF for a yr, we;ve become very close and in love. he wants to get engaged soon and talks about a future with me all the time.. and I think about it to.. BUT just recently he said some things that have made me think. EX: in the begining iv asked him things about his past like if he has ever cheated been to strip club, things like that. he said no. now a yr later i find out thats not the truth & he says he doesnt remember denyin those things but that he must of lied bc he want to forget his past. he has lied about other little things, nothing like cheating or betrayal but still!! he said he was afraid of me judging him and wanted to have that chance with me. (yes i might of come off as a tough girl w a guard up and bit of a perfectionist when we started dating) I think im going to see past this ..he seems very sorry & says he wasn't trying to decieve me. But Y do i feel so hurt then? Am i now in that category as girls who say "but i know he really loves me" "he cheated but he still loves me" or the best is lol "at least hes coming home to me" I REALLY fear i guess being that way?? i have put him through hell for this being dishonest thing... whats your input? forgive & forget or leave?