Hi, I thought exactly the same as you, my op was booked for Jan 4th, being the NHS it was cancelled, thankfully, because I had booked a holiday fairly soon after, thinking I would be ok and I wasn't.
It does depend on what you're having done, I had mastectomy and Lipo. I genuinely thought I'd be fully functional after about 1, 2 to 3 weeks but not so. You really do have to look after yourself fully and take a lot of care following this.
I ate only healthy foods, had a pre/pro biotic to boost my immunity as was fearful of getting an infection, kept the wounds as clean and sanitised as possible etc etc. I took things very steady and did exactly what my surgeon told me to.
If you check out the Ask the Doc bit, I asked these great guys a question about sun-bathing and it's a no no, as I am due to go to a very hot climate in 3 weeks time, so even though I love the sun, I will be covering that area up.
I am now 6 weeks post op and only just able to move fairly freely. There is still tightness and lifting my arms above my head is impossible yet. The incision sites are healing nicely but there are still some stitches there even now! You can definitely see them at this point as The Todd said. My scars are very minimal even though I had the lot done. She went in so close to the nipple it sort of blends in.
I am very pleased with the result and am not trying to put you off at all, in fact I'd say go for it, big time, BUT please be aware your recovery time may be much longer than you think.
I've read some people's posts on here and have been shocked, ie pulling their own stitches out etc etc, this is so dangerous. Being a nurse myslef, albeit psychiatric, I have seen some horrendous wound infections through people's impatience and basic stupidity.
Be kind to your body mate, you only get one!
Hope that helps.