Having a handicapped child is a little like turning 80--suddenly the little things you've done all your life are considered remarkable. "She takes care of that big house all by herself!" (Who else would do it, pray tell?) Martyrdom is foisted upon you with no act of bravery required on your part whatsoever.

And you become "deep." Never mind that you didn't survive the Holocaust and don't really know what it's like to be discriminated against; you now have angst of your own. Suddenly you qualify.

Choose your spouse carefully. (You should have thought of this sooner, of course; you may have to make the best of what you have.)

The existentialists are right--you alone are in for the duration. The teachers, therapists and miscellaneous experts will come and go. If you're lucky, however, there are two of you in this particular mess and one of you can be freaking out while the other copes. (I assume you were not so foolish as to hurry your spouse into child-rearing before he/she was ready and thus giving him/her the opening of "These kids were your idea!")

Your life would be perfect without your handicapped child. You would stop smoking; you would be thin; you would be in the midst of an exciting career. Your house would be spotless; your sex life, a dream; your spiritual life, in order. None of this is true, of course, but take what comfort you can.

It is difficult to keep a low profile when one is out with a severely retarded child. The halls of the Smithsonian echo marvelously with Jordan's high-pitched whoops. The items in other people's grocery carts are infinitely more interesting than those in one's own. (I have noticed this myself, so have some sympathy here.)

Unable to become the expert in familial rights that his siblings are, 10-year-old Jordan has studied Gandhi and passive resistance. He will lie down halfway across 18th and K and resist the length of the walk and the heat of the day through several cycles of the light while I attempt to drag him to the curb.

Don't stew about the public's reaction. Like Parisians, they rarely offer assistance, but they do leave you to your plight without interfering. (The day Jordan entwined his fingers in the waist-length hair of a woman in front of us in the bank and the day he zeroed out the cash register in the Giant I could have handled a little helpful interference.)

You may as well show some tolerance, however, to the man in the street. He cannot know how soft your child's back is, nor how delighted he is with a bunch of helium balloons. You have the advantage of seeing the satisfaction your son takes in constructing elaborate tents out of sofa cushions and sheets, the pleasure he takes in a warm radiator on a cold morning, and the ecstasy that is his when he runs off with a pair of his dad's socks. The stranger is nonplused by the unpredictability of your whooping offspring and is trying hard to act cool.

You will encounter people who tell you a handicapped child is a mission from God; these people usually don't read the funnies either, which is a sure sign of taking oneself too seriously. Some will say it's for the best; (best for whom?). Some will argue that he can't miss what he never had. (I'm still sensitive about not having a date for the senior prom, so am particularly skeptical of this last theory.)

A paucity of funds will plague you, but this thing you can't afford and feel will change your life--or your child's--probably won't. We finally got a piano for Jordan to pound on and soon had a piano shell in the family room and a bucket of hammers in the basement.

Even without a handicapped child it is necessary to pull oneself up short every now and then and consider how hollow are the lives of the very rich. Remember the image of the shabby, but book-filled home that you brought away from Little Women and made your ideal. Those homes in Dickens were always well scrubbed and you may fall a little short here. A rather brazen visitor once pointed out that the same fly had been legs-up on top of a window frame on her last visit. (It was a very small fly and a very tall window.)

Cultivate a single friend. This is good advice for any parent, but a parent of a handicapped child will get double points for mothering when she comes up with beautiful homemade Halloween costumes. As a neighbor declared, "I notice whenever you get in over your head, she's involved." Yes, thank heavens, she is.

Your friend, if he or she is intelligent enough to bother with, probably won't be too keen on getting involved in the nitty-gritty of raising a handicapped child, but might listen to you whine and get enthused with you in frivolous endeavors like jam making and more serious ones like painting posters for protest rallies. Such is the stuff of life and you couldn't manage it alone. As you are indescribably tied down, it is useful to have a portable friend.

Put the child in respite care every two years and throw an enormous bash. Pull out all the stops, and let people know you're still in the land of the living.

Invite Kate Hepburn to lunch. She won't come, but there is always that half of 1 percent chance that she might, so it is great inspiration for digging out.

Take heed of Caitlin Thomas in Not Quite Posthumous Letters to My Daughter:

"The more you do, the more you can do. As inversely, the less you do, the less you can do. So keep going, even if you have no lighted indication of where to go."

And take comfort in the promise that there's sex after 60.