|Thin shall never win. Girth shall move the earth.|
You really learn what you're capable of. You learn what difficult really is. Your Excel spreadsheets at work suddenly seem a lot less daunting after grinding out your 8th set of heavy squats, don't they? Ladies, you learn that you don't HAVE to ask your boyfriend to carry the grocery bags for you; you're strong enough to do it yourself.
One of the best lessons training will teach you is the importance of doing the things you don't want to do, or don't think are important. You love doing bench and bi's, right? Don't think you need to do squats because you don't play sports? It'll work for a period of time, and then you'll present with some really uncomfortable imbalances...and have chicken legs. Don't want to wash your dishes or lift up the toilet seat when you pee? See how that works for you, dude.
Training makes you get out of your comfort zone. It makes you learn how to keep moving forward, you have to constantly evolve. As soon as you get good at something in the weight room, there is something else to overcome. Got a decent back-squat? Time to front-squat. You lost a few pounds? Great! Time to lose some more. Complacency is bad, it's a rut. The only difference between a rut and a grave is the depth.
Get outside of your comfort zone. It's easy to leave work and go home and watch The Real Housewives of BlahBlahBlah. Try challenging yourself. So many people insist on the best for themselves at work and in relationships, but are willing to just let their own physical well-being slide down the drain.
Please, go lift something heavy!