Good thread and a lot that I can agree with. My favorite line, these days is, "I can be here...or home cleaning toilets." (cleaned up, depending on the company). But it's true. I'm competitive as the next person but, in the end, it's just tennis. My paycheck will not change at the end of the day.
Particularly don't like losing to something I don't like (personality-wise) or someone I think I could/should/have beaten or when my loss means the team lost....but it's a perspective thing. Friends or family members with terminal illnesses, heck even your own sick kids, are there enough funds to pay the bills and food in the fridge...all of that's more important than any final score. I always sleep well at night...having played that day, regardless of the outcome.
A 3.5 masquerading around with a 4.0 mask on.