^in an oversimplification, until I have £34500 in I dont assume I'll anything most months.
Dh has 45k in and wins a prize most months^
That's how I also think about it. You also have to remember the odds of winning will varying according to a normal distribution over a population level, so while each bond has a 1 in 34 000 chance of winning and if you have this amount, you should win one prize a month, the chances of winning 0, 2 or more prizes each month is also reasonably likely and it's probably best to look at winnings over time, where it's more likely that you'll be closer to the average payout over a year, or over 5 or 10 years. But even over that time, there will still be people in the tail of the curve at either end, who will be much more or less lucky than average.
For example, taking the PP who's had £1000 for 15 years, that's 1000 x 15 x 12 = 180 000 'bond draws' so the average number of prizes over that time with that amount should be 5, and actually higher, because the payout rate was higher in the past, so that poster is quite unlucky, but not impossibly as there will always be a few people with that holding who never win.
If you're interested in the statistics, have a look at the MSE calculator. You can put different holdings in and calculate the chance of winning over various time periods. If you then click on the 'dig into the details' tabs, you can see graphs and odds of the amounts people win over all holders, not just a tiny snapshot as seen on this thread.
www.moneysavingexpert.com/savings/premium-bonds-calculator/#result
The calculator only goes up to 5 years, but for £1000 over 5 years, it says that 17% of people will win nothing, 82% will win at least £25 and smaller numbers of people will win larger amounts.