Best admits the result was hard to take, especially as the whole world was watching at Twickenham, but he insists his team will be stronger for the experience.
"We have to be aiming to be at the Aviva next year," said Best.
"We can't pat ourselves on the back for being in the Heineken Cup Final when four years ago you thought you were never going to get out of the group.
"You have to be looking to win this trophy."
Prior to Saturday's showdown in London, Ulster hadn't appeared in the Heineken Cup Final for 13 years.
Last season was the first time they had made it past the pool stages since their title-winning campaign in 1999, while their latest European adventure had featured some truly memorable success stories.
Ulster opened their campaign with a home win over French giants and eventual semi-finalists ASM Clermont Auvergne and went on to hammer former champions Leicester Tigers 41-7 at Ravenhill in Round 5.
That remarkable result against one of the competition's perennial big hitters was followed by an away win over Munster at fortess Thomond Park, a venue where only Leicester had won previously in 17 years of the Heineken Cup.
But while that lengthy list of achievements will surely provide some crumbs of comfort further down the line, Best admits it is the pain of defeat that will push Ulster forward in future seasons.
"It was heartbreaking watching Leinster lift the trophy, but that is what you learn from," added Best.
"You have to watch that and that has to drive you for next year. Defeats like this and watching Leinster lift the trophy has to be in our minds now for the next 12 months."