My brother was thinking that he could always start teaching later in life, but the reality is, tomorrow never comes.

弟弟曾经想他可以在退休后再去教书，现实是，退休还不知道要等到何年何月。

youdao

You want to correct them, but if you correct these, later another thing comes. So, you have never really a life without a problem.

但是，即使你改得了这些事，随后就冒出别的事来，生活中不可能没有问题的。

youdao

Involvement of young people invariably moves into the 'too difficult' box, to be dealt with later, but later never comes.

BBC: How we can help children improve their health