Is it normal that i still smell marijuana on me?

I use to smoke marijuana daily for 5 years, and then I was on too much other shit (meth, crack,coke,ect) so I was sent to treatment by my parents. I've been sober since 11/1/13. So it's been around almost 15 months of me being off everything. But my friend told me my hands smell like weed, and I can kinda smell it. I just don't see how or why they still smell.