Simply as I understand it, and with some rounding of the figures.
In 2007 we were riding high. The state was collecting €47bn a year in tax and spending the same on public services. The national debt was 30% of GDP
By 2010 the state was collecting €31bn a year in tax and had a €60bn bill to bail out the banks. It continued to spend €50bn a year. We were definitely banjaxed.
To finance this it spent the pension reserve, €20bn, and borrowed the rest. National debt rose to 120% of GDP
Gradually through tax increases USC etc. and growth in the economy the tax take recovered to €45bn in 2015. We are still borrowing today, though less than before. National debt is down to 92% of GDP.
In 2007 we were in a bad place and heading down. Today we are in a very slightly better place but heading up.
To make an analogy, in 2007 we were like a worker on €47k a year who took a pay cut to €31k and was told that things were not looking good for keeping the job. He also had a small mortgage. So to maintain his standard of living and pay some unexpected bills (the bank bail out) he spent his savings, (the pension reserve) and drew down on his mortgage.
Today the wages have gone back up to €45k and we have stopped drawing down the mortgage, though the savings are gone and we are still increasing the overdraft. People tell us that the job is looking more secure than it was.
source for tax receipts figures
http://databank.finance.gov.ie/FinDataBank.aspx?rep=TaxYrTrend