Well, while i'm still not sure WHAT i believe, i went ALL OUT for my first holidays. I always felt like i'd missed out on the "fun" stuff as a kid, and with kids of my own, couldn't wait.
Halloween: decorated my house to the hilt! graveyard in the front yard, bats hanging from the ledges in the entry way, etc.
Thanksgiving: Didn't change much from the witness days other than the fact that we actually did it on THANKSGIVING DAY instead of the day after when the "turkeys were on sale."
Xmas: XMAS LIGHTS GALLORE!!!! LIGHTS EVERYwhere. my house looked beautiful. Got the biggest tree i could afford and all the trimmings. Couldn't wait. House looked so pretty adorned with all the red bows, candles, tinsel, etc. I cried when my lights came on for the first time. Always wanted lights. (Had a lot of drive-by's ...people wanted to see if i'd actually have the GUTS to decorate!)
As for the "meaning" of these holidays: Not really too into the meaning yet. Just enjoying the fluff, ya know?