I don't really change them. (I wash them though while I sleep. Take a shower, go down change my undergarments, etc, throw everything into the washer and go to bed, dry them when I get up and throw them on and go to work.)

I don't own a lot of pants, so not very often. I mostly rotate (like someone else mentioned) between the few that I have and I also have two pairs of "home pants"...

Once a week, pants dont get so dirty

its not about how clean they are....its about appearing being poor and dirty.   people should have more than enough pants for a different pair every day, anyways.

You have all different colors I assume? I ask this because if you have (3) pairs of black and (4) pairs of blue, how does one know if the pair of blue jeans you wore on Wednesday weren't the same ones you wore on Monday?

I know I only have Black, Blue and sometimes I'll have a faded blue or faded black. No green, red, brown, etc... for me, or whatever other colors are out there.

I second this. I change everything else daily or every other day, depending on where I am or what I have been doing. But with "pants", I usually wear jeans, and I only change them if there is something noticably wrong with them, like if they have a stain or if they smell. Jeans are made out of very durable material, and my legs are never really dirty or sweaty, so I never feel the urge to change them until after a week or two. As for my school trousers, I often change them once or twice a week.

EDIT: What I meant to say, was I change them when I shit in them.

2-3 times a week. You don't need to wash your jeans after a day's use IMO.

However, you change your underwear every two days? I'd say 99% of people do it daily, me included.

I change boxers/underwear everyday. Pants and shirt usually two days, unless I got visibly dirty or sweated. I do however change my socks every three days or so.

unless you have a closet full of the exact same pants, i dont see how you would be unable to tell them apart.

I don't spend my free time looking for blue jeans that look different. I don't care if the stitching or pockets look the same, so you won't find me with one with one design on the back pockets and another pair of blue jeans with a different design. The way I do it is this... the pants look nice, fit nice, are comfortable and are priced right, alright, buy (2) pairs, maybe (3).

I don't care about anything else and my wallet thanks me. I know when I dress I am clean, even if the jeans look the same. I couldn't care less what anyone else thinks.

Pretty looking jeans with differentiating features isn't what got me a good paying job, a kid and a loving family, you know what I mean? To me all this "Other might think..." means nothing as those people have more important things in life to worry about.

Another thing I do is that if my jeans are beginning to fade big time but are still in great shape otherwise, I would buy some dye, let them soak, air dry them and then wash them. I get a lot of mileage out of my jeans. I buy shirts when they fade though as they don't look right if I dye them, especially since my shirts aren't one solid color.