Young people start by regularly investing as they have no existing capital to invest. We have noticed that our clients who are now middle-aged and have continued to invest regularly are often in a much better financial position than those who just stopped investing because they felt they had accumulated enough (when in reality they had not) or those who never upped their contributions over the years.
The best time to invest regularly was yesterday, the second best time is today. You cannot go back in time but you can start now which is better than not at all.
The other advantage of investing regularly until retirement is you get used to living on your salary less your investment contributions. This means that when you lose your salary at retirement, the shortfall between what you were receiving in work and what you are receiving now is less and you have more capital to make up the shortfall.
Also, when the markets are down, the real winners are regular investors as they benefit from "pound cost averaging" which means that each month they buy more units as the prices are cheaper.
So don't prevaricate. If you are still working, pick up the phone and get us to set up or increase your regular investment plan. 100% of your contributions are invested, you do not pay any initial costs to set up a plan.