Outstanding advice. I went back ~35 after a career up until then in network engineering and information security, though I went back and picked up a finance degree. gw0ntum makes a valuable addition. You're going to find it awkward, especially when you have some profs your age or even younger. Some suggestions I'd make:
1. BE HUMBLE: even if you're an alpha, don't play one. set it aside and adopt an alternate persona. your classmates not only don't want to hear about your experience but they're ready to reject you if you show any signs of it. instead, humility is your friend. when you kick ass in assignments and show you're naturally good at some things, your younger classmates will likely respect you then for it. but always keep the humility as your persona. they're going to be intimidated by the age difference and when they find that 15-20 years of age difference really doesn't mean jack u-know-what, they'll be cool with you.
2. HANDLE PROFS CAREFULLY: show your creativity, innovativness, eagerness, etc. by DOING, not by saying. this screws so many nontraditional students up. yes, its important to let the prof know you're eager to learn/succeed. but do it by doing, not by showing off. understand that you're an outlier, so every subtle action you make in the classroom will have 10x the effect. this pisses off your classmates and makes your prof uncomfortable.
3. FIND YOUR PERSONA AND STICK TO IT: my dad's long-time faculty at a university that has a good amount of nontraditional students. i've learned that even the faculty has stereotypes of the nontrads. eager beavers (over-eager volunteer for everything desperate to show their worth low self esteem types), suck-ups (total poseurs that will flunk out but will suck up at first and try to play the 'hey prof, i'm a grown-up like you, give me preference'), one-class-ponys (typically 60+ gals who take one class and blow the damn curve cuz they have no freaking life outside of that one class), over-committers (usually the nontrads who have just come back to academic world and are so clingy and over-committing trying to prove their worth to self and prof), and dominators (nontrads that want to give input to everything, dominate the discussion, share their "worldly" experience on everything and embarrass everyone in the room except themselves). Those are not good choices. Find something subtle, quiet and driven. Sit in the front row, kick ass and let your work show your drive. Let the prof call you out because you get stuff right. They will balance the dialog and keep you from being seen as a show-off - hey, when your work is good, that's the game.
4. FRIENDSHIPS: Be open, kind and friendly to all. I ended up with friends spanning the total range - from girl jocks to geeks to poet-thinkers to hard core achievers. All I had to do was smile, be relaxed, be damn good, and be a team player.
It's a weird situation but if you handle it right, it'll be very rewarding, and that degree does open up tons of doors. Good luck!