Shri, that would have been an SMC reset. You can Google it and do it yourself at home.
I find most Macs last a good 4-5 years now, with the easiest component to fail first being the battery of hard disk (the conventional one as opposed to SSDs), but these are relatively easy and cheap to replace.
OS wise, sure you're gonna get new features, and battery enhancements with firmware updates, but there isn't anything forcing to you to update, except for iPad and iPhone above iPhone 5 which requires an iTunes version which requires at least 10.6.8 (snow leopard). I still see plenty of older Macs still running on older OS (10.6, 10.7, 10.8) with no problems and no need to update.