Encouragement is cheap when it costs nothing. It gets expensive the week their course starts and the evenings you used to share go to a textbook.
The generous version knows what it is spending. You are not only cheering. You are absorbing the rearranged Tuesdays, the tiredness, the version of them that is temporarily worse company.
There is a specific pleasure in it that nobody advertises: watching a person become more themselves while you hold the ordinary end of things steady. That isn't a lesser role. Most ambitions that got anywhere had somebody doing the washing-up behind them.