Just as my 12-month-old daughter is learning to take her first wobbly steps, I fear I am taking some of my last. As I watch her faltering progress across the kitchen floor, I know just how she feels. Like a toddler, I too need to hold on to the furniture and walls for support, and invariably I stumble and fall before I reach my objective.
Unlike her, I don't bounce quite so easily.
It's 10 years since the doctor gave me my life-changing diagnosis. In the intervening years multiple sclerosis (MS) has stolen my legs with such stealth that I hardly noticed the theft.
At first symptoms came and went. MS started with pins and needles in my thighs and a bit of muscle weakness in my legs. Other symptoms were less easy to define.
Sometimes I had the peculiar sensation that I was wearing a very tight waistcoat, especially if I had just got out of the bath. Sometimes I felt like that man who ran the London marathon in a diving suit, a strange combination of discomfort and exhaustion.
MS is the most common disabling neurological condition affecting young adults.
Around 85,000 people in the UK have MS. Gradual paralysis and a range of other nasty symptoms, including eyesight and bladder problems, are the result of damage to the protective sheath surrounding nerve fibres of the central nervous system. For some people, MS is characterised by periods of relapse and remission, while for others it is progressive - a slow, wobbly walk to a wheelchair.
With each fresh attack, which lasted from a few days to several months, I was left with a little more residual disability. Sometimes I would have problems with my eyesight, sometimes with my bladder. Like a car with too many miles on the clock, I never knew what was going to conk out next.
Where once I could take stairs two at a time, now I had to hold the banister to pull myself up. My foot started dragging and catching on paving stones. A trip to the shops took on a more literal meaning.
As MS slowly advanced, I adjusted to doing things differently. Over the course of five years, the distance I could walk without using a stick became shorter. Then I needed two crutches to get about, sometimes a wheelchair.
But despite all that, I felt in pretty good shape and continued to work full time as a civil servant.
Certainly, I could not do the high hurdles or limbo dance anymore, but at the age of 39, I felt content to leave my partying days behind me. It was not until we had children that I realised quite how much I missed being physically active.
Although we both knew I had MS before we decided to try to have children, it didn't really seem an issue. The key consideration for us was whether MS could be inherited. Our GP put our minds at rest. MS was not genetic, he said. There may be a slightly increased chance of the children developing the disease, but the risk was very, very small.
The more immediate concern might be getting pregnant in the first place, the doctor suggested. It wasn't only fingers and toes that can experience paralysis. But I was confident that it shouldn't be a problem, providing my wife didn't play too hard to get and insist on being chased up the stairs and round the bedroom.
Five years on and we have Tim, four, and one-year-old Alice. It is fantastic being a father, but physically tough. The nappy changing, cooking, feeding, bathing and driving exhaust me - and for the most part I am just watching.
When we go to the park to feed the ducks, I push the pram. I always push the pram, as it is the only way I can walk a short distance. I never go out alone with Tim in case he runs off and I can't chase after him.
My eldest is beginning to suspect I am not quite like other dads. Information is on a need to know basis, and we have decided they will not really need to know details for some years yet. Daddy keeps them entertained by falling over and spilling things. If I don't hurt myself, it's not a big deal. The trick is to make it all matter of fact.
But that does not stop the questions. "Why are you wobbly? Why do you use a stick and wheelchair?" I explain my legs don't work sometimes as well as they should. And then it's swiftly on to the next thing.
Naturally, I want to protect my children and shield them from my MS. But I can't hide or cure the disease and we were never going to grant MS the status of becoming a big family secret. By not talking about something, you empower it and it becomes more threatening precisely because it is hushed up. The children would be vulnerable.
Their unspoken fears might include my premature death from MS or indeed their own deaths. MS is a very inclusive condition. Everyone in the family is affected.
As the disease has remorselessly strengthened its grip and I have slowly lost mine, I have had to make adjustments. I realised early on that I could not walk around with a baby in my arms, so I bum shuffle my way down the stairs and play with the children on the floor. I drive an automatic car with hand-controls and have temporarily mothballed my squash racket and rollerblades.
My four-year-old scolded me yesterday for being slow. "What do you mean?" I said with a theatrical raised eyebrow. "I am not so much slow, as very careful."
Without a hint of malice or anger he walked a couple of steps forward with his arms out, mimicking my gait - a cross between The Mummy and a Teletubby. My throat tightened. His impersonation was terribly cruel because it was astutely accurate.
Whatever the future holds, I know it is going to take many bedtime stories about the tortoise and the hare for him to begin to understand.
